pH ['pē-'āch] -n

  1. a measure of acidity and alkalinity of a solution that is a number on a scale on which a value of 7 represents neutrality and lower numbers indicate increasing acidity and higher numbers increasing alkalinity and on which each unit of change represents a tenfold change in acidity or alkalinity and that is the negative logarithm of the effective hydrogen-ion concentration or hydrogen-ion activity in gram equivalents per liter of the solution
  2. the condition represented by a pH number

PH -abbr

  1. pinch hit
  2. public health
  3. Purple Heart

Phae·dra ['fē-drə] -n

  1. a daughter of Minos who marries Theseus and falls in love with her stepson Hippolytus

Pha·e·thon ['fā-ə-tən, -,thän] -n

  1. a son of Helios who drives his father's sun-chariot through the sky but loses control and is struck down by a thunderbolt of Zeus

pha·eton ['fā-ə-tən] -n

  1. any of various light four-wheeled horse-drawn vehicles
  2. touring car

phage ['fāj also 'fäzh] -n

  1. bacteriophage

phago·cyte ['fa-gə-,sīt] -n, adj

  1. a cell (as a white blood cell) that engulfs and consumes foreign material (as microorganisms) and debris

phago·cy·tize ['fa-gə-sə-,tīz, -,sī-] -vt

  1. phagocytose

phago·cy·tose [-sə-,tōs, -sī-, -,tōz] -vt

  1. to consume by phagocytosis

phago·cy·to·sis [,fa-gə-sə-'tō-səs, -sī-] -n, adj

  1. the engulfing and usu. the destruction of particulate matter by phagocytes

phal·ae·nop·sis [,fa-lə-'näp-səs] -n

  1. any of a genus ( Phalaenopsis) of ornamental epiphytic orchids of southeastern Asia and Australia having fleshy leaves and large showy flowers with broad lateral petals

pha·lange ['fā-,lanj, fə-', fā-'] -n

  1. phalanx

pha·lan·ge·al [,fā-lən-'jē-əl, ,fa-; fə-'lan-jē-, fā-] -adj

  1. of or relating to a phalanx or the phalanges

pha·lan·ger [fə-'lan-jər, 'fā-,] -n

  1. any of various small to medium-sized marsupial mammals (family Phalangeridae) of the Australian region that are chiefly arboreal and nocturnal and usu. densely furred

phal·an·stery ['fa-lən-,ster-ē] -n

  1. a Fourierist cooperative community
  2. a self-contained structure housing such a community
  3. something resembling a Fourierist phalanstery

pha·lanx ['fā-,laŋ(k)s, Brit usu 'fa-] -n

  1. a body of heavily armed infantry in ancient Greece formed in close deep ranks and files
  2. a body of troops in close array
  3. one of the digital bones of the hand or foot of a vertebrate
  4. a massed arrangement of persons, animals, or things
    • a phalanx of armed guards
  5. an organized body of persons
    • a phalanx of lawyers

phal·a·rope ['fa-lə-,rōp] -n

  1. any of a genus ( Phalaropus) of small shorebirds related to sandpipers but distinguished by their lobed toes and preference for swimming

phal·lic ['fa-lik] -adj, adv

  1. of or relating to phallicism
    • a phallic cult
  2. of, relating to, or resembling a phallus
  3. relating to or being the stage of psychosexual development in psychoanalytic theory that follows the anal stage and during which a child becomes interested in his or her own sexual organs

phal·li·cism ['fa-lə-,si-zəm] -n

  1. the worship of the generative principle as symbolized by the phallus

phal·lo·cen·tric [,fa-lə-'sen-trik] -adj, n

  1. centered on or emphasizing the masculine point of view

phal·lo·crat·ic [,fa-lə-'kra-tik, -(,)lō-] -adj

  1. relating to, resulting from, or advocating masculine power and dominance

phal·lus ['fa-ləs] -n

  1. a symbol or representation of the penis
  2. penis

phan·er·o·gam ['fa-nə-rə-,gam, fə-'ner-ə-] -n

  1. a seed plant or flowering plant : spermatophyte

phan·er·o·phyte ['fa-nə-rə-,fīt, fə-'ner-ə-] -n

  1. a perennial plant that bears its perennating buds well above the surface of the ground

Phan·er·o·zo·ic [,fa-nə-rə-'zō-ik] -adj, n

  1. of, relating to, or being an eon of geologic history that comprises the Paleozoic, Mesozoic, and Cenozoic or the corresponding systems of rocks

phan·tasm ['fan-,ta-zəm] -n, adj

  1. : a product of fantasy: as
  2. delusive appearance : illusion
  3. ghost, specter
  4. a figment of the imagination
  5. a mental representation of a real object

phan·tas·ma [fan-'taz-mə] -n

  1. phantasm

phan·tas·ma·go·ria [(,)fan-,taz-mə-'gȯr-ē-ə] -n, adj

  1. an exhibition of optical effects and illusions
  2. a constantly shifting complex succession of things seen or imagined
  3. a scene that constantly changes
  4. a bizarre or fantastic combination, collection, or assemblage

phantasy ['fan-tə-sē, -zē] -n

(variant of fantasy)

  1. hallucination
  2. fancy
  3. the free play of creative imagination
  4. : a creation of the imaginative faculty whether expressed or merely conceived: as
  5. a fanciful design or invention
  6. a chimerical or fantastic notion
  7. fantasia
  8. imaginative fiction featuring esp. strange settings and grotesque characters called also fantasy fiction
  9. caprice
  10. the power or process of creating esp. unrealistic or improbable mental images in response to psychological need
    • an object of fantasy
  11. a mental image or a series of mental images (as a daydream) so created
    • sexual fantasies of adolescence
  12. a coin usu. not intended for circulation as currency and often issued by a dubious authority (as a government-in-exile)

phan·tom ['fan-təm] -n, adv or adj

  1. something apparent to sense but with no substantial existence : apparition
  2. something elusive or visionary
  3. an object of continual dread or abhorrence
    • the phantom of disease and want
  4. something existing in appearance only
  5. a representation of something abstract, ideal, or incorporeal
    • she was a phantom of delight -- William Wordsworth

phantom -adj

  1. of the nature of, suggesting, or being a phantom : illusory
  2. fictitious, dummy
    • phantom voters

phantom limb -n

  1. an often painful sensation of the presence of a limb that has been amputated called also phantom pain

phar -abbr

  1. pharmacopoeia
  2. pharmacy

pha·raoh ['fer-(,)ō, 'fā-(,)rō] -n

  1. a ruler of ancient Egypt
  2. tyrant

pharaoh ant -n

  1. a small red ant ( Monomorium pharaonis) that is a common household pest

phar·a·on·ic [,fer-ā-'ä-nik] -adj

  1. of, relating to, or characteristic of a pharaoh or the pharaohs
  2. enormous in size or magnitude
    • pharaonic construction projects

phar·i·sa·ic [,fa-rə-'sā-ik] -adj

  1. pharisaical
  2. of or relating to the Pharisees

phar·i·sa·ical [-'sā-ə-kəl] -adj, adv, n

  1. marked by hypocritical censorious self-righteousness

phar·i·sa·ism ['fa-rə-(,)sā-,i-zəm] -n

  1. the doctrines or practices of the Pharisees
  2. pharisaical character, spirit, or attitude : hypocrisy

phar·i·see ['fa-rə-(,)sē] -n

  1. a member of a Jewish sect of the intertestamental period noted for strict observance of rites and ceremonies of the written law and for insistence on the validity of their own oral traditions concerning the law
  2. a pharisaical person

pharm -abbr

  1. pharmaceutical; pharmacist; pharmacy

phar·ma ['fär-mə] -n

  1. a pharmaceutical company
  2. large pharmaceutical companies as a group

phar·ma·ceu·ti·cal [,fär-mə-'sü-ti-kəl] -adj, adv

  1. of, relating to, or engaged in pharmacy or the manufacture and sale of pharmaceuticals
    • a pharmaceutical company

pharmaceutical -n

  1. a medicinal drug

phar·ma·cist ['fär-mə-sist] -n

  1. a person licensed to engage in pharmacy

pharmaco- -comb form

  1. medicine : drug
    • pharmaco logy

phar·ma·co·dy·nam·ics [,fär-mə-kō-dī-'na-miks, -də-] -n pl but sing in constr, adj, adv

  1. a branch of pharmacology dealing with the reactions between drugs and living systems

phar·ma·co·ge·net·ics [,fär-mə-kō-je-'ne-tiks] -n pl but sing in constr

  1. the study of how genetic differences among individuals cause varied responses to a drug

phar·ma·co·ge·no·mics [,fär-mə-kō-jē-'nō-miks] -n pl but sing in constr, adj

  1. the science concerned with ways to compensate for genetic differences in patients which cause varied responses to a single drug

phar·ma·cog·no·sy [,fär-mə-'käg-nə-sē] -n, adj

  1. a branch of pharmacology dealing with medicinal substances of biological origin and esp. medicinal substances obtained from plants

phar·ma·co·ki·net·ics [-kō-kə-'ne-tiks, -kō-kī-] -n pl but sing in constr, adj

  1. the study of the bodily absorption, distribution, metabolism, and excretion of drugs
  2. the characteristic interactions of a drug and the body in terms of its absorption, distribution, metabolism, and excretion

phar·ma·col·o·gy [,fär-mə-'kä-lə-jē] -n, adj, adv

  1. the science of drugs including their origin, composition, pharmacokinetics, therapeutic use, and toxicology
  2. the properties and reactions of drugs esp. with relation to their therapeutic value

phar·ma·co·poe·ia [-kə-'pē-ə] -n, adj

  1. a book describing drugs, chemicals, and medicinal preparations
  2. one issued by an officially recognized authority and serving as a standard
  3. a collection or stock of drugs

phar·ma·co·ther·a·py [,fär-mə-kō-'ther-ə-pē] -n

  1. the treatment of disease and esp. mental illness with drugs

phar·ma·cy ['fär-mə-sē] -n

  1. the art, practice, or profession of preparing, preserving, compounding, and dispensing medical drugs
  2. a place where medicines are compounded or dispensed
  3. drugstore
  4. pharmacopoeia

PharmD -abbr

  1. doctor of pharmacy

pha·ryn·geal [,fa-rən-'jē-əl, fə-'rin-j(ē-)əl] -adj

  1. relating to or located or produced in the region of the pharynx

phar·yn·gi·tis [,fa-rən-'jī-təs] -n

  1. inflammation of the pharynx

phar·ynx ['fa-riŋ(k)s] -n

  1. the muscular tubular passage of the vertebrate digestive and respiratory tracts extending from the back of the nasal cavity and mouth to the esophagus
  2. a differentiated part of the alimentary canal in some invertebrates that may be thickened and muscular, eversible and toothed, or adapted as a suctorial organ

phase ['fāz] -n, adj

  1. a particular appearance or state in a regularly recurring cycle of changes
    • phase s of the moon
  2. a distinguishable part in a course, development, or cycle
    • the early phase s of her career
  3. an aspect or part (as of a problem) under consideration
  4. the point or stage in a period of uniform circular motion, harmonic motion, or the periodic changes of any magnitude varying according to a simple harmonic law to which the rotation, oscillation, or variation has advanced from its standard position or assumed instant of starting
  5. a homogeneous, physically distinct, and mechanically separable portion of matter present in a nonhomogeneous physicochemical system
  6. an individual or subgroup distinguishably different in appearance or behavior from the norm of the group to which it belongs
  7. the distinguishing peculiarity
  8. to adjust so as to be in a synchronized condition
  9. to conduct or carry out by planned phases
  10. to introduce in stages usu. used with in
    • phase in new models

phasecontrast -adj

  1. of or employing the phase-contrast microscope

phasecontrast microscope -n

  1. a microscope that translates differences in phase of the light transmitted through or reflected by the object into differences of intensity in the image called also phase microscope

phase·down ['fāz-,dau̇n] -n

  1. a gradual reduction (as in operations or size) : a slowing down by phases

phase down -vt

  1. to reduce the size or amount of by phases
    • phase down the program
  2. to undergo reduction by phases

phase modulation -n

  1. modulation of the phase of a radio carrier wave by voice or other signal

phase·out ['fāz-,au̇t] -n

  1. a gradual stopping (as in operations or production) : a closing down by phases

phase out -vt

  1. to discontinue the practice, production, or use of by phases
  2. to stop production or operation by phases

phas·mid ['faz-məd] -n, adj

  1. any of an order (Phasmatodea syn. Phasmida) of large cylindrical or sometimes flattened chiefly tropical insects (as a walking stick) that have long legs, strictly phytophagous habits, and incomplete metamorphosis and that include forms resembling leaves or twigs

phat ['fat] -adj

  1. highly attractive or gratifying : excellent
    • a phat beat moving through my body -- Tara Roberts

phat·ic ['fa-tik] -adj, adv

  1. of, relating to, or being speech used for social or emotive purposes rather than for communicating information

PhB -abbr

  1. bachelor of philosophy

PhD -abbr

  1. doctor of philosophy

pheas·ant ['fe-zᵊnt] -n

  1. any of numerous large often long-tailed and brightly colored Old World gallinaceous birds ( Phasianusand related genera of the family Phasianidae) including many raised as ornamental or game birds
  2. any of various birds resembling a pheasant

phel·lem ['fe-,lem] -n

  1. a layer of usu. suberized cells produced outwardly by a phellogen

phel·lo·derm ['fe-lə-,dərm] -n

  1. a layer of parenchyma produced inwardly by a phellogen

phel·lo·gen ['fe-lə-jən] -n

  1. a secondary meristem that initiates phellem and phelloderm in the periderm of a stem or root called also cork cambium

phen- -comb form

  1. related to or derived from benzene
    • phen ol
  2. containing phenyl
    • pheno barbital

phe·na·caine ['fē-nə-,kān, 'fe-] -n

  1. a crystalline base C 18H 22N 2O 2or its hydrochloride used as a local anesthetic

phen·ac·e·tin [fi-'na-sə-tən] -n

  1. a white crystalline compound C 10H 13NO 2formerly used to ease pain or fever but withdrawn because of its serious side effects called also acetophenetidin

phen·a·kite ['fe-nə-,kīt, 'fē-] -n

  1. a hard glassy mineral that consists of a silicate of beryllium and occurs esp. in rhombohedral crystals

phen·an·threne [fə-'nan-,thrēn] -n

  1. a crystalline tricyclic aromatic hydrocarbon C 14H 10of coal tar isomeric with anthracene

phen·a·zine ['fe-nə-,zēn] -n

  1. a yellowish crystalline base C 12H 8N 2used esp. in organic synthesis

phen·cy·cli·dine [(,)fen-'si-klə-,dēn, -'sī-, -dən] -n

  1. a piperidine derivative C 17H 25N used chiefly in the form of its hydrochloride esp. as a veterinary anesthetic and sometimes illicitly as a psychedelic drug called also angel dust PCP

phe·net·ic [fi-'ne-tik] -adj

  1. of or relating to taxonomic analysis that emphasizes the overall similarities of characteristics among biological taxa without regard to phylogenetic relationships

phe·net·ics [-tiks] -n pl but sing in constr, n

  1. a system of biological classification based on phenetic methods

phenfen ['fen-,fen] -n

  1. fen-phen

phen·met·ra·zine [(,)fen-'me-trə-,zēn] -n

  1. a sympathomimetic stimulant C 11H 15NO used in the form of its hydrochloride as an appetite suppressant

phe·no·bar·bi·tal [,fē-nō-'bär-bə-,tȯl] -n

  1. a crystalline barbiturate C 12H 12N 2O 3used as a hypnotic, sedative, and anticonvulsant

phe·no·bar·bi·tone [-bə-,tōn] -n

  1. phenobarbital

phe·no·copy ['fē-nə-,kä-pē] -n

  1. a phenotypic variation that is caused by unusual environmental conditions and resembles the normal expression of a genotype other than its own

phe·no·cryst [-,krist] -n, adj

  1. one of the prominent embedded crystals of a porphyry

phe·nol ['fē-,nōl, -,nȯl, fi-'] -n

  1. a corrosive poisonous crystalline acidic compound C 6H 5OH present in the tars of coal and wood that in dilute solution is used as a disinfectant
  2. any of various acidic compounds analogous to phenol and regarded as hydroxyl derivatives of aromatic hydrocarbons

phe·no·late ['fē-nə-,lāt] -n

  1. phenoxide

phe·no·lat·ed ['fē-nə-,lā-təd] -adj

  1. treated, mixed, or impregnated with phenol

phe·no·lic [fi-'nō-lik, -'nä-] -adj

  1. of, relating to, or having the characteristics of a phenol
  2. containing or derived from a phenol
  3. of, relating to, or being a phenolic

phenolic -n

  1. a usu. thermosetting resin or plastic made by condensation of a phenol with an aldehyde and used esp. for molding and insulating and in coatings and adhesives called also phenolic resin
  2. phenol

phe·nol·o·gy [fi-'nä-lə-jē] -n, adj, adv

  1. a branch of science dealing with the relations between climate and periodic biological phenomena (as bird migration or plant flowering)
  2. periodic biological phenomena that are correlated with climatic conditions

phe·nol·phtha·lein [,fē-nᵊl-'tha-lē-ən, -'tha-,lēn, -'thā-] -n

  1. a white or yellowish-white crystalline compound C 20H 14O 4used in analysis as an indicator because its solution is brilliant red in alkalies and is decolorized by acids and in medicine as a laxative

phenol red -n

  1. a red crystalline compound C 19H 14O 5S used esp. as an acid-base indicator

phe·nom ['fē-,näm, fi-'näm] -n

  1. phenomenon
  2. a person of phenomenal ability or promise

phe·nom·e·na [fi-'nä-mə-nə, -,nä] -n

  1. phenomenon

phe·nom·e·nal [fi-'nä-mə-nᵊl] -adj, adv

  1. : relating to or being a phenomenon: as
  2. known through the senses rather than through thought or intuition
  3. concerned with phenomena rather than with hypotheses
  4. extraordinary, remarkable

phe·nom·e·nal·ism [-nə-,li-zəm] -n, n or adj, adj, adv

  1. a theory that limits knowledge to phenomena only
  2. a theory that all knowledge is of phenomena and that what is construed to be perception of material objects is simply perception of sense-data

phe·nom·e·no·log·i·cal [fi-,nä-mə-nə-'lä-ji-kəl] -adj, adv

  1. of or relating to phenomenology
  2. phenomenal
  3. of or relating to phenomenalism

phe·nom·e·nol·o·gy [fi-,nä-mə-'nä-lə-jē] -n

  1. the study of the development of human consciousness and self-awareness as a preface to or a part of philosophy
  2. a philosophical movement that describes the formal structure of the objects of awareness and of awareness itself in abstraction from any claims concerning existence
  3. the typological classification of a class of phenomena
    • the phenomenology of religion
  4. an analysis produced by phenomenological investigation

phe·nom·e·non [fi-'nä-mə-,nän, -nən] -n

  1. an observable fact or event
  2. an object or aspect known through the senses rather than by thought or intuition
  3. a temporal or spatiotemporal object of sensory experience as distinguished from a noumenon
  4. a fact or event of scientific interest susceptible to scientific description and explanation
  5. a rare or significant fact or event
  6. an exceptional, unusual, or abnormal person, thing, or occurrence

phe·no·thi·a·zine [,fē-nō-'thī-ə-,zēn] -n

  1. a greenish-yellow crystalline compound C 12H 9NS used as an anthelmintic and insecticide esp. in veterinary practice
  2. any of various phenothiazine derivatives (as chlorpromazine) that are used as tranquilizing agents esp. in the treatment of schizophrenia

phe·no·type ['fē-nə-,tīp] -n, adj, adv

  1. the observable properties of an organism that are produced by the interaction of the genotype and the environment

phen·ox·ide [fi-'näk-,sīd] -n

  1. a salt of a phenol esp. in its capacity as a weak acid

phen·ter·mine ['fen-tər-,mēn] -n

  1. an anorectic drug C 10H 15N used in the form of its hydrochloride to treat obesity

phen·tol·amine [fen-'tä-lə-,mēn, -mən] -n

  1. an adrenergic blocking agent C 17H 19N 3O used esp. in the diagnosis and treatment of hypertension due to pheochromocytoma

phe·nyl ['fe-nᵊl, 'fē-] -n, adj

  1. a monovalent aryl radical C 6H 5 derived from benzene by removal of one hydrogen atom often used in combination

phe·nyl·al·a·nine [,fe-nᵊl-'a-lə-,nēn, ,fē-] -n

  1. an essential amino acid C 9H 11NO 2that is converted in the normal body to tyrosine

phen·yl·bu·ta·zone [,fe-nᵊl-'byü-tə-,zōn] -n

  1. a drug C 19H 20N 2O 2that is used for its analgesic and anti-inflammatory properties esp. in the treatment of arthritis, gout, and bursitis

phen·yl·eph·rine [-'e-,frēn, -frən] -n

  1. a sympathomimetic agent C 9H 13NO 2that is used in the form of its hydrochloride as a vasoconstrictor, a mydriatic, a nasal decongestant, and by injection to raise the blood pressure

phen·yl·eth·yl·amine [,fe-nᵊl-,e-thəl-'a-,mēn, ,fē-] -n

  1. a neurotransmitter C 8H 11N that is an amine resembling amphetamine in structure and pharmacological properties
  2. any of its derivatives

phe·nyl·ke·ton·uria [,fe-nᵊl-,kē-tᵊn-'u̇r-ē-ə, ,fē-, -'yu̇r-] -n, n or adj

  1. an inherited metabolic disorder caused by an enzyme deficiency resulting in accumulation of phenylalanine and its metabolites in the blood causing usu. severe mental retardation and seizures unless phenylalanine is restricted from the diet beginning at birth abbr. PKU

phen·yl·pro·pa·nol·amine [,fe-nᵊl-,prō-pə-'nȯ-lə-,mēn, ,fē-, -'nō-; -nȯ-'la-,mēn] -n

  1. a sympathomimetic drug C 9H 13NO used in the form of its hydrochloride esp. as a nasal and bronchial decongestant and as an appetite suppressant

phen·yl·thio·car·ba·mide [,fe-nᵊl-,thī-ō-'kär-bə-,mīd, ,fē-] -n

  1. a crystalline compound C 7H 8N 2S that is extremely bitter or tasteless depending on the presence or absence of a single dominant gene in the taster called also phenylthiourea PTC

phen·yl·thio·urea [-,thī-ō-yu̇-'rē-ə] -n

  1. phenylthiocarbamide

phe·nyt·o·in [fə-'ni-tə-wən] -n

  1. a crystalline anticonvulsant compound C 15H 12N 2O 2used in the form of its sodium salt in the treatment of epilepsy called also diphenylhydantoin

pheo·chro·mo·cy·to·ma [,fē-ə-,krō-mə-sə-'tō-mə, -sī-] -n

  1. a tumor that is derived from chromaffin cells and is usu. associated with paroxysmal or sustained hypertension

phe·re·sis [fə-'rē-səs] -n

  1. apheresis

pher·o·mone ['fer-ə-,mōn] -n, adj

  1. a chemical substance that is usu. produced by an animal and serves esp. as a stimulus to other individuals of the same species for one or more behavioral responses

phew [a voiceless bilabial fricative usu followed by a voiceless (y)ü orsound; often read as 'f(y)ü] -interj

  1. used to express relief or fatigue
  2. used to express disgust at or as if at an unpleasant odor

phi ['fī] -n

  1. the 21st letter of the Greek alphabet

phi·al ['fī(-ə)l] -n

  1. vial

Phi Be·ta Kap·pa [,fī-,bā-tə-'ka-pə] -n

  1. a person winning high scholastic distinction in an American college or university and being elected to membership in a national honor society founded in 1776

Phil -abbr

  1. Philippians

phil- -comb form

  1. loving : having an affinity for
    • philo progenitive

Phil·a·del·phia lawyer [,fi-lə-'del-fyə-, -fē-ə-] -n

  1. a lawyer knowledgeable in the most minute aspects of the law

Philadelphia pepper pot -n

  1. pepper pot

phil·a·del·phus [,fi-lə-'del-fəs] -n

  1. mock orange

phi·lan·der [fə-'lan-dər] -vi, n

  1. to have casual or illicit sex with a woman or with many women
  2. to be sexually unfaithful to one's wife

phil·an·throp·ic [,fi-lən-'thrä-pik] -adj, adv

  1. of, relating to, or characterized by philanthropy : humanitarian
  2. dispensing or receiving aid from funds set aside for humanitarian purposes

phi·lan·thro·pist [fə-'lan(t)-thrə-pist] -n

  1. one who practices philanthropy

phi·lan·thro·poid [-,pȯid] -n

  1. a person who works for a philanthropic organization

phi·lan·thro·py [-pē] -n

  1. goodwill to fellowmen
  2. active effort to promote human welfare
  3. a philanthropic act or gift
  4. an organization distributing or supported by philanthropic funds

phi·lat·e·list [fə-'la-tə-list] -n

  1. a specialist in philately : one who collects or studies stamps

phi·lat·e·ly [fə-'la-tə-lē] -n, adj, adv

  1. the collection and study of postage and imprinted stamps : stamp collecting

Phi·le·mon [fə-'lē-mən, fī-] -n

  1. a friend and probable convert of the apostle Paul
  2. a letter written by St. Paul to a Christian living in the area of Colossae and included as a book in the New Testament
  3. a poor aged Phrygian in Greek mythology who with his wife Baucis treats a disguised Zeus hospitably and is rewarded by him with a splendid temple

phil·har·mon·ic [,fi-lər-'mä-nik, -(,)lär-; ,fil-(,)här-] -n

  1. symphony orchestra

phil·hel·lene [(,)fil-'he-,lēn] -adj, n

  1. admiring Greece or the Greeks

Phi·lip·pi·ans [fə-'li-pē-ənz] -n pl but sing in constr

  1. a hortatory letter written by St. Paul to the Christians of Philippi and included as a book in the New Testament

phi·lip·pic [fə-'li-pik] -n

  1. a discourse or declamation full of bitter condemnation : tirade

Phil·ip·pine mahogany ['fi-lə-,pēn-] -n

  1. any of several Philippine dipterocarp timber trees (genera Shorea, Parashorea,and Pentacme) with wood resembling that of the true mahoganies
  2. its wood

phi·lis·tia [fə-'lis-tē-ə] -n

  1. the class or world of cultural philistines

Phi·lis·tine ['fi-lə-,stēn; fə-'lis-tən, -,tēn; 'fi-lə-stən] -n, adj

  1. a native or inhabitant of ancient Philistia
  2. a person who is guided by materialism and is usu. disdainful of intellectual or artistic values
  3. one uninformed in a special area of knowledge

Phil·lips ['fi-ləps] -adj

  1. of, relating to, or being a screw having a head with a cross slot or the corresponding screwdriver

phil·lu·men·ist [fi-'lü-mə-nist] -n

  1. one who collects matchbooks or matchbox labels

Phi·loc·te·tes [fi-'läk-tə-,tēz, ,fi-läk-'tē-tēz] -n

  1. a Greek archer who uses the bow of Hercules to slay Paris at Troy

phil·o·den·dron [,fi-lə-'den-drən] -n

  1. any of various aroid plants (as of the genus Philodendron) that are cultivated for their showy foliage

phi·lol·o·gy [fə-'lä-lə-jē also fī-] -n, adj, adv

  1. the study of literature and of disciplines relevant to literature or to language as used in literature
  2. linguistics
  3. historical and comparative linguistics
  4. the study of human speech esp. as the vehicle of literature and as a field of study that sheds light on cultural history

Phil·o·mel ['fi-lə-,mel] -n

  1. nightingale

Phil·o·me·la [,fi-lə-'mē-lə] -n

  1. an Athenian princess in Greek mythology raped and deprived of her tongue by her brother-in-law Tereus, avenged by the killing of his son, and changed into a nightingale while fleeing from him

phil·o·pro·gen·i·tive [,fi-lə-prō-'je-nə-tiv] -adj, n

  1. tending to produce offspring : prolific
  2. of, relating to, or characterized by love of offspring

philos -abbr

  1. philosophy

phi·lo·sophe [,fē-lə-'zȯf] -n

  1. one of the deistic or materialistic writers and thinkers of the 18th century French Enlightenment

phi·los·o·pher [fə-'lä-s(ə-)fər] -n

  1. a person who seeks wisdom or enlightenment : scholar, thinker
  2. a student of philosophy
  3. a person whose philosophical perspective makes meeting trouble with equanimity easier
  4. an expounder of a theory in a particular area of experience
  5. one who philosophizes

philosopher's stone -n

  1. an imaginary stone, substance, or chemical preparation believed to have the power of transmuting baser metals into gold and sought by alchemists
  2. an elusive or imaginary key to success called also philosophers' stone

phil·o·soph·i·cal [,fi-lə-'sä-fi-kəl also -'zä-] -adj, adv

  1. of or relating to philosophers or philosophy
  2. based on philosophy
  3. characterized by the attitude of a philosopher
  4. calm or unflinching in the face of trouble, defeat, or loss

philosophical analysis -n

  1. analytic philosophy

phi·los·o·phise [fə-'lä-sə-,fīz] -vb, n

(variant of philosophize)

  1. to reason in the manner of a philosopher
  2. to expound a moralizing and often superficial philosophy
  3. to consider from or bring into conformity with a philosophical point of view

phi·los·o·phize [fə-'lä-sə-,fīz] -vb, n

  1. to reason in the manner of a philosopher
  2. to expound a moralizing and often superficial philosophy
  3. to consider from or bring into conformity with a philosophical point of view

phi·los·o·phy [fə-'lä-s(ə-)fē] -n

  1. all learning exclusive of technical precepts and practical arts
  2. the sciences and liberal arts exclusive of medicine, law, and theology
    • a doctor of philosophy
  3. the 4-year college course of a major seminary
  4. physical science
  5. ethics
  6. a discipline comprising as its core logic, aesthetics, ethics, metaphysics, and epistemology
  7. pursuit of wisdom
  8. a search for a general understanding of values and reality by chiefly speculative rather than observational means
  9. an analysis of the grounds of and concepts expressing fundamental beliefs
  10. a system of philosophical concepts
  11. a theory underlying or regarding a sphere of activity or thought
    • the philosophy of war
  12. the most basic beliefs, concepts, and attitudes of an individual or group
  13. calmness of temper and judgment befitting a philosopher

philosophy of life

  1. an overall vision of or attitude toward life and the purpose of life
  2. any of various philosophies that emphasize human life or life in general

phil·ter ['fil-tər] -n

  1. a potion credited with magical power
  2. a potion, drug, or charm held to have the power to arouse sexual passion

phil·tre ['fil-tər] -n

(variant of philter)

  1. a potion credited with magical power
  2. a potion, drug, or charm held to have the power to arouse sexual passion

phi phenomenon -n

  1. apparent motion resulting from an orderly sequence of stimuli (as lights flashed in rapid succession a short distance apart on a sign) without any actual motion being presented to the eye

phish·ing ['fi-shiŋ] -n

  1. a scam by which an e-mail user is duped into revealing personal or confidential information which the scammer can use illicitly

phiz ['fiz] -n

  1. face

phleb- -comb form

  1. vein
    • phleb itis

phle·bi·tis [fli-'bī-təs] -n

  1. inflammation of a vein

phle·bol·o·gy [fli-'bä-lə-jē] -n

  1. a branch of medicine concerned with the veins

phle·bo·to·mus fever [fli-'bä-tə-məs-] -n

  1. sandfly fever

phle·bot·o·my [fli-'bä-tə-mē] -n

  1. the letting of blood for transfusion, diagnosis, or experiment, and esp. formerly in the treatment of disease called also venesection

Phleg·e·thon ['fle-gə-,thän] -n

  1. a river of fire in Hades

phlegm ['flem] -n, adj

  1. the one of the four humors in early physiology that was considered to be cold and moist and to cause sluggishness
  2. viscid mucus secreted in abnormal quantity in the respiratory passages
  3. dull or apathetic coldness or indifference
  4. intrepid coolness or calm fortitude

phleg·mat·ic [fleg-'ma-tik] -adj, adv

  1. resembling, consisting of, or producing the humor phlegm
  2. having or showing a slow and stolid temperament

phlo·em ['flō-,em] -n

  1. a complex tissue in the vascular system of higher plants that consists mainly of sieve tubes and elongated parenchyma cells usu. with fibers and that functions in translocation and in support and storage

phloem necrosis -n

  1. a pathological state in a plant characterized by brown discoloration and disintegration of the phloem
  2. a fatal disease of the American elm caused by a phytoplasma transmitted by a leafhopper ( Scaphoideus luteolus)

phloem ray -n

  1. a vascular ray or part of a vascular ray that is located in phloem

phlo·gis·tic [flō-'jis-tik] -adj

  1. of or relating to phlogiston
  2. of or relating to inflammations and fevers

phlo·gis·ton [-tən] -n

  1. the hypothetical principle of fire regarded formerly as a material substance

phlog·o·pite ['flä-gə-,pīt] -n

  1. a usu. brown to red form of mica

phlox ['fläks] -n

  1. any of a genus ( Phloxof the family Polemoniaceae, the phlox family) of American annual or perennial herbs that have red, purple, white, or variegated flowers, a salverform corolla with the stamens on its tube, and a 3-valved capsular fruit

pH meter -n

  1. an apparatus for measuring the strength or the amount of acid present in a mixture or solution called also acidimeter

pho·bia ['fō-bē-ə] -n

  1. an exaggerated usu. inexplicable and illogical fear of a particular object, class of objects, or situation

pho·bic ['fō-bik] -adj, n

  1. of, relating to, affected with, or constituting phobia

phoe·be ['fē-bē] -n

  1. any of a genus ( Sayornis) of the tyrant flycatcher family
  2. a flycatcher ( S. phoebe) of the eastern U.S. that has a slight crest and is plain grayish brown above and yellowish white below

Phoe·be ['fē-bē] -n

  1. artemis

Phoe·bus ['fē-bəs] -n

  1. apollo
  2. sun

Phoe·ni·cian [fi-'nē-shən, -'ni-] -n, adj

  1. a native or inhabitant of ancient Phoenicia
  2. the Semitic language of ancient Phoenicia

phoe·nix ['fē-niks] -n, adj

  1. a legendary bird which according to one account lived 500 years, burned itself to ashes on a pyre, and rose alive from the ashes to live another period
  2. a person or thing likened to the phoenix

phon- -comb form

  1. sound : voice : speech
    • phon ate
    • phono graph

pho·nate ['fō-,nāt] -vi, n

  1. to produce vocal sounds and esp. speech

phone ['fōn] -n

  1. a speech sound considered as a physical event without regard to its place in the sound system of a language
  2. telephone
  3. earphone
  4. telephone

phone card -n

  1. a prepaid card used for making telephone calls

phonein ['fōn-,in] -n

  1. a call-in show (as on radio)

pho·ne·mat·ic [,fō-nē-'ma-tik] -adj

  1. phonemic

pho·neme ['fō-,nēm] -n

  1. any of the abstract units of the phonetic system of a language that correspond to a set of similar speech sounds (as the velar k of cooland the palatal k of keel) which are perceived to be a single distinctive sound in the language

pho·ne·mic [fə-'nē-mik, fō-] -adj, adv

  1. of, relating to, or having the characteristics of a phoneme
  2. constituting members of different phonemes (as n and m in English)
  3. distinctive

pho·ne·mics [-miks] -n pl but sing in constr, n

  1. a branch of linguistic analysis involving the study of phonemes
  2. the structure of a language in terms of phonemes

phone sex -n

  1. prerecorded sex-oriented telephone messages available to those who call a commercial service
  2. sex-oriented telephone conversations (as with an operator employed by a commercial service or with a lover)

phone tag -n

  1. telephone tag

pho·net·ic [fə-'ne-tik] -adj, adv

  1. of or relating to spoken language or speech sounds
  2. of or relating to the science of phonetics
  3. : representing the sounds and other phenomena of speech: as
  4. constituting an alteration of ordinary spelling that better represents the spoken language, that employs only characters of the regular alphabet, and that is used in a context of conventional spelling
  5. representing speech sounds by means of symbols that have one value only
  6. employing for speech sounds more than the minimum number of symbols necessary to represent the significant differences in a speaker's speech

phonetic alphabet -n

  1. a set of symbols (as the IPA) used for phonetic transcription
  2. any of various systems of identifying letters of the alphabet by means of code words in voice communication

pho·ne·ti·cian [,fō-nə-'ti-shən also ,fä-] -n

  1. a specialist in phonetics

pho·net·ics [fə-'ne-tiks] -n pl but sing in constr

  1. the system of speech sounds of a language or group of languages
  2. the study and systematic classification of the sounds made in spoken utterance
  3. the practical application of this science to language study

pho·nic ['fä-nik also 'fō-] -adj, adv

  1. of, relating to, or producing sound : acoustic
  2. of or relating to the sounds of speech
  3. of or relating to phonics

pho·nics ['fä-niks, 1 is also 'fō-] -n pl but sing in constr

  1. the science of sound : acoustics
  2. a method of teaching beginners to read and pronounce words by learning the phonetic value of letters, letter groups, and esp. syllables

pho·no ['fō-(,)nō] -n

  1. phonograph

pho·no·car·dio·gram [,fō-nə-'kär-dē-ə-,gram] -n

  1. a graphic representation of heart sounds made by means of a microphone, amplifier, and recording equipment

pho·no·car·di·og·ra·phy [-,kär-dē-'ä-grə-fē] -n, adj

  1. the process of producing a phonocardiogram

pho·no·gram ['fō-nə-,gram] -n

  1. a character or symbol used to represent a word, syllable, or phoneme
  2. a succession of orthographic letters that occurs with the same phonetic value in several words (as the ightof bright, fight,and flight)

pho·no·graph ['fō-nə-,graf] -n

  1. an instrument for reproducing sounds by means of the vibration of a stylus or needle following a spiral groove on a revolving disc or cylinder

pho·nog·ra·pher [fə-'nä-grə-fər, fō-] -n

  1. a specialist in phonography

pho·no·graph·ic [,fō-nə-'gra-fik, 1 is also ,fä-] -adj, adv

  1. of or relating to phonography
  2. of or relating to a phonograph

pho·nog·ra·phy [fə-'nä-grə-fē, fō-] -n

  1. spelling based on pronunciation
  2. a system of shorthand writing based on sound

pho·no·lite ['fō-nə-,līt] -n

  1. a gray or green volcanic rock consisting essentially of orthoclase and nepheline

pho·nol·o·gy [fə-'nä-lə-jē, fō-] -n, adj, adv

  1. the science of speech sounds including esp. the history and theory of sound changes in a language or in two or more related languages
  2. the phonetics and phonemics of a language at a particular time

pho·non ['fō-,nän] -n

  1. a quantum of vibrational energy (as in a crystal)

pho·no·tac·tics [,fō-nə-'tak-tiks] -n pl but sing in constr, adj

  1. the area of phonology concerned with the analysis and description of the permitted sound sequences of a language

pho·ny ['fō-nē] -adj, adv, n

  1. : not genuine or real: as
  2. intended to deceive or mislead
  3. intended to defraud : counterfeit
  4. arousing suspicion : probably dishonest
    • something phony about the story
  5. having no basis in fact : fictitious
    • phony publicity stories
  6. false, sham
    • a phony name
  7. : making a false show: as
  8. hypocritical
  9. specious
    • has a phony poetic elegance -- New Republic

phony -n

  1. one that is phony
  2. counterfeit, fake often used with up
    • a paper phonied up on the spur of the moment -- William Faulkner

pho·nyba·lo·ney [-bə-'lō-nē] -adj

  1. phony

phoo·ey ['fü-ē] -interj

  1. used to express repudiation or disgust

pho·rate ['fȯr-,āt] -n

  1. a very toxic organophosphate systemic insecticide C 7H 17O 2PS 3

phos·gene ['fäz-,jēn] -n

  1. a colorless gas COCl 2of unpleasant odor that is a severe respiratory irritant that has been used in chemical warfare

phosph- -comb form

  1. phosphorus
    • phosph ide
  2. phosphate
    • phospho fructokinase

phos·pha·tase ['fäs-fə-,tās, -,tāz] -n

  1. : an enzyme that accelerates the hydrolysis and synthesis of organic esters of phosphoric acid and the transfer of phosphate groups to other compounds:
  2. alkaline phosphatase
  3. acid phosphatase

phos·phate ['fäs-,fāt] -n

  1. a salt or ester of a phosphoric acid
  2. the trivalent anion PO 4 3derived from phosphoric acid H 3PO 4
  3. an organic compound of phosphoric acid in which the acid group is bound to nitrogen or a carboxyl group in a way that permits useful energy to be released (as in metabolism)
  4. an effervescent drink of carbonated water with a small amount of phosphoric acid flavored with fruit syrup
  5. a phosphatic material used for fertilizers

phosphate rock -n

  1. a rock that consists largely of calcium phosphate usu. together with other minerals (as calcium carbonate), is used in making fertilizers, and is a source of phosphorus compounds

phos·phat·ic [fäs-'fa-tik, -'fā-] -adj

  1. of, relating to, or containing phosphoric acid or phosphates
    • phosphatic fertilizers

phos·pha·tide ['fäs-fə-,tīd] -n, adj

  1. phospholipid

phos·pha·ti·dyl [,fäs-fə-'tī-dᵊl, fäs-'fa-tə-dᵊl] -n

  1. any of several monovalent groups (RCOO) 2C 3H 5OPO(OH) that are derived from phosphatidic acids

phos·pha·ti·dyl·cho·line [,fäs-fə-,tī-dᵊl-'kō-,lēn, (,)fäs-,fa-tə-dᵊl-] -n

  1. lecithin

phos·pha·ti·dyl·eth·a·nol·amine [-,e-thə-'nä-lə-,mēn, -'nō-] -n

  1. any of a group of phospholipids that occur esp. in blood plasma and the white matter of the central nervous system called also cephalin

phos·pha·tize ['fäs-fə-,tīz] -vt, n

  1. to treat with phosphoric acid or a phosphate
  2. to change to a phosphate or phosphates

phos·pha·tu·ria [,fäs-fə-'tu̇r-ē-ə, -'tyu̇r-] -n

  1. the excessive discharge of phosphates in the urine

phos·phene ['fäs-,fēn] -n

  1. a luminous impression due to excitation of the retina

phos·phide [-,fīd] -n

  1. a binary compound of phosphorus with a more electropositive element or group

phos·phine [-,fēn] -n

  1. any of various derivatives of phosphine analogous to amines but weaker as bases
  2. a colorless poisonous flammable gas PH 3that is a weaker base than ammonia and that is used esp. to fumigate stored grain

phos·phite [-,fīt] -n

  1. a salt or ester of phosphorous acid

phos·pho·cre·a·tine [,fäs-(,)fō-'krē-ə-,tēn] -n

  1. a compound C 4H 10N 3O 5P of creatine and phosphoric acid that is found esp. in vertebrate muscle where it is an energy source for muscle contraction

phos·pho·di·es·ter·ase [-dī-'es-tə-,rās, -,rāz] -n

  1. a phosphatase (as from snake venom) that acts on diesters (as some nucleotides) to hydrolyze only one of the two ester groups

phos·pho·enol·pyr·uvate [,fäs-,fō-ə-,nȯl-pī-'rü-,vāt, -,nōl-, -,pī(-ə)r-'yü-] -n

  1. a salt or ester of phosphoenolpyruvic acid

phos·pho·enol·pyr·uvic acid [-pī-'rü-vik-, -,pī(-ə)r-'yü-vik-] -n

  1. the phosphate H 2CC(OPO 3H 2)COOH of the enol form of pyruvic acid that is formed as an intermediate in carbohydrate metabolism

phos·pho·fruc·to·ki·nase [,fäs-(,)fō-,frək-tō-'kī-,nās, -,frük-, -,fru̇k-, -,nāz] -n

  1. an enzyme that functions in carbohydrate metabolism and esp. in glycolysis by catalyzing the transfer of a second phosphate (as from ATP) to fructose

phos·pho·glu·co·mu·tase [-,glü-kō-'myü-,tās, -,tāz] -n

  1. an enzyme found in all plant and animal cells that catalyzes the reversible isomerization of glucose-1-phosphate to glucose-6-phosphate

phos·pho·glyc·er·al·de·hyde [-,gli-sə-'ral-də-,hīd] -n

  1. a phosphate of glyceraldehyde C 3H 5O 3(H 2PO 3) that is formed esp. in anaerobic metabolism of carbohydrates by the splitting of a diphosphate of fructose

phos·pho·glyc·er·ate [,fäs-fō-'gli-sə-,rāt] -n

  1. a salt or ester of phosphoglyceric acid

phos·pho·gly·cer·ic acid [-gli-'ser-ik-] -n

  1. either of two isomeric acid phosphates C 3H 5O 3(OPO 3H 2) of glyceric acid that are formed as intermediates in photosynthesis and in carbohydrate metabolism

phos·pho·ki·nase [,fäs-fō-'kī-,nās, -,nāz] -n

  1. kinase

phos·pho·li·pase [-'lī-,pās, -,pāz] -n

  1. any of several enzymes that hydrolyze lecithins or phosphatidylethanolamines called also lecithinase

phos·pho·lip·id [-'li-pəd] -n

  1. any of numerous lipids (as lecithins and phosphatidylethanolamines) in which phosphoric acid as well as a fatty acid is esterified to glycerol and which are found in all living cells and in the bilayers of cell membranes

phos·pho·mono·es·ter·ase [-,mä-nō-'es-tə-,rās, -,rāz] -n

  1. a phosphatase that acts on monoesters

phos·pho·ni·um [fäs-'fō-nē-əm] -n

  1. a monovalent cation PH 4 analogous to ammonium and derived from phosphine
  2. an organic derivative of phosphonium (as (C 2H 5) 4P )

phos·pho·pro·tein [,fäs-fō-'prō-,tēn, -'prō-tē-ən] -n

  1. any of various proteins (as casein) that contain combined phosphoric acid

phos·phor ['fäs-fər, -,fȯr] -n

  1. a phosphorescent substance
  2. a luminescent substance that emits light when excited by radiation (as electrons) and is used esp. in fluorescent lamps and cathode-ray tubes

phosphor bronze -n

  1. a bronze of great hardness, elasticity, and toughness that contains a small amount of phosphorus

phos·pho·resce [,fäs-fə-'res] -vi

  1. to exhibit phosphorescence

phos·pho·res·cence [-'re-sᵊn(t)s] -n

  1. luminescence that is caused by the absorption of radiations (as light or electrons) and continues for a noticeable time after these radiations have stopped
  2. an enduring luminescence without sensible heat

phos·pho·res·cent [-sᵊnt] -adj, adv

  1. exhibiting phosphorescence

phos·pho·ric [fäs-'fȯr-ik, -'fär-; 'fäs-f(ə-)rik] -adj

  1. of, relating to, or containing phosphorus esp. with a valence higher than in phosphorous compounds

phosphoric acid -n

  1. a syrupy or deliquescent tribasic acid H 3PO 4used esp. in preparing phosphates (as for fertilizers), in rust-proofing metals, and esp. formerly as a flavoring in soft drinks called also orthophosphoric acid
  2. a compound (as pyrophosphoric acid or metaphosphoric acid) consisting of phosphate groups linked directly to each other by oxygen

phos·pho·rite ['fäs-fə-,rīt] -n, adj

  1. a fibrous concretionary apatite
  2. phosphate rock

phos·pho·rol·y·sis [,fäs-fə-'rä-lə-səs] -n, adj

  1. a reversible reaction analogous to hydrolysis in which phosphoric acid functions in a manner similar to that of water with the formation of a phosphate (as glucose-1-phosphate in the breakdown of liver glycogen)

phos·pho·rous ['fäs-f(ə-)rəs; fäs-'fȯr-əs] -adj

  1. of, relating to, or containing phosphorus esp. with a valence lower than in phosphoric compounds

phosphorous acid -n

  1. a deliquescent crystalline acid H 3PO 3used esp. as a reducing agent and in making phosphites

phos·pho·rus ['fäs-f(ə-)rəs] -n

  1. a phosphorescent substance or body
  2. one that shines or glows in the dark
  3. a nonmetallic element of the nitrogen family that occurs widely esp. as phosphates

phos·pho·ryl ['fäs-fə-,ril] -n

  1. a usu. trivalent group PO

phos·phor·y·lase [fäs-'fȯr-ə-,lās, -,lāz] -n

  1. any of the enzymes that catalyze phosphorolysis with the formation of organic phosphates

phos·phor·y·late [-,lāt] -vt, adj

  1. to cause (an organic compound) to take up or combine with phosphoric acid or a phosphorus-containing group

phos·phor·y·la·tion [,fäs-,fȯr-ə-'lā-shən] -n

  1. the process of phosphorylating a chemical compound either by reaction with inorganic phosphate or by transfer of phosphate from another organic phosphate
  2. the enzymatic conversion of carbohydrates into their phosphoric esters in metabolic processes

phot- -comb form

  1. light : radiant energy
    • phot on
    • photo graphy
  2. photograph : photographic
    • photo engraving
  3. photoelectric
    • photo cell

pho·tic ['fō-tik] -adj, adv

  1. of, relating to, or involving light esp. in relation to organisms
  2. penetrated by light esp. of the sun
    • the photic zone of the ocean

pho·to ['fō-(,)tō] -n

  1. photograph

photo -vb

  1. photograph
  2. photographic

pho·to·ag·ing [,fō-tō-'ā-jiŋ] -n

  1. the cumulative detrimental effects (as wrinkles or dark spots) on skin that result from long-term exposure to sunlight and esp. ultraviolet light

pho·to·au·to·tro·phic [,fō-tō-,ȯ-tə-'trō-fik] -adj, n, adv

  1. autotrophic and utilizing energy from light
    • green plants are photoautotrophic

pho·to·bi·ol·o·gy [,fō-tō-(,)bī-'ä-lə-jē] -n, adj

  1. a branch of biology that deals with the effects on living organisms of radiant energy (as light)

pho·to·cath·ode [-'ka-,thōd] -n

  1. a cathode that emits electrons when exposed to radiant energy and esp. light

pho·to·cell ['fō-tə-,sel] -n

  1. photoelectric cell

pho·to·chem·i·cal [,fō-tō-'ke-mi-kəl] -adj, adv

  1. of, relating to, or resulting from the chemical action of radiant energy and esp. light
    • photochemical smog
  2. of or relating to photochemistry
    • photochemical studies

pho·to·chem·is·try [-'ke-mə-strē] -n

  1. a branch of chemistry that deals with the effect of radiant energy in producing chemical changes
  2. photochemical properties
    • the photochemistry of gases
  3. photochemical processes
    • photochemistry of vision

pho·to·chro·mic [,fō-tə-'krō-mik] -adj, n

  1. capable of changing color on exposure to radiant energy (as light)
    • photochromic glass
  2. of, relating to, or utilizing the change of color shown by a photochromic substance
    • a photochromic process

pho·to·co·ag·u·la·tion [-kō-,a-gyə-'lā-shən] -n

  1. a surgical process of coagulating tissue by means of a precisely oriented high-energy light source (as a laser)

pho·to·com·pose [,fō-tō-kəm-'pōz] -vt, n

  1. to set (as reading matter) by photocomposition

pho·to·com·po·si·tion [-,käm-pə-'zi-shən] -n

  1. composition of text directly on film or photosensitive paper for reproduction

pho·to·con·duc·tive [-kən-'dək-tiv] -adj

  1. having, involving, or operating by photoconductivity

pho·to·con·duc·tiv·i·ty [-,kän-,dək-'ti-və-tē, -kən-] -n

  1. electrical conductivity that is affected by exposure to electromagnetic radiation (as light)

pho·to·copy ['fō-tə-,kä-pē] -n

  1. a copy of usu. printed material made with a process in which an image is formed by the action of light usu. on an electrically charged surface

photocopy -vt, n

  1. to make a photocopy of
  2. to make a photocopy

pho·to·cur·rent ['fō-tō-,kər-ənt, -,kə-rənt] -n

  1. a stream of electrons produced by photoelectric or photovoltaic effects

pho·to·de·com·po·si·tion [-,dē-,käm-pə-'zi-shən] -n

  1. photolysis

pho·to·de·grad·able [-di-'grā-də-bəl] -adj

  1. chemically degradable by the action of light
    • photodegradable plastics

pho·to·de·tec·tor [-di-'tek-tər] -n

  1. any of various devices for detecting and measuring the intensity of radiant energy through photoelectric action

pho·to·di·ode [-'dī-,ōd] -n

  1. a photoelectric semiconductor device for detecting and often measuring radiant energy (as light)

pho·to·dis·in·te·gra·tion [-dis-,in-tə-'grā-shən] -n, vt

  1. disintegration of the nucleus of an atom caused by absorption of radiant energy (as light)

pho·to·dis·so·ci·a·tion [-di-,sō-sē-'ā-shən, -shē-] -n, vb

  1. dissociation of the molecules of a substance (as water) caused by absorption of radiant energy

pho·to·du·pli·ca·tion [-,dü-plə-'kā-shən, -,dyü-] -n, vb

  1. the process of making photocopies

pho·to·dy·nam·ic [-(,)dī-'na-mik] -adj, adv

  1. of, relating to, or having the property of intensifying or inducing a toxic reaction to light (as in the destruction of cancer cells stained with a light-sensitive dye) in a living system

pho·to·elec·tric [,fō-tō-i-'lek-trik] -adj, adv

  1. involving, relating to, or utilizing any of various electrical effects due to the interaction of radiation (as light) with matter

photoelectric cell -n

  1. an electronic device whose electrical properties are modified by the action of light

photoelectric effect -n

  1. the emission of free electrons from a metal surface when light strikes it

pho·to·elec·tron [,fō-tō-i-'lek-,trän] -n, adj

  1. an electron released in photoemission

pho·to·emis·sion [-i-'mi-shən] -n, adj

  1. the release of electrons from a usu. solid material (as a metal) by means of energy supplied by incidence of radiation and esp. light

pho·to·en·grave [-in-'grāv] -vt, n

  1. to make a photoengraving of

pho·to·en·grav·ing -n

  1. a photomechanical process for making linecuts and halftone cuts by photographing an image on a metal plate and then etching
  2. a plate made by photoengraving
  3. a print made from such a plate

pho·toes·say ['fō-tō-,e-,sā] -n

  1. a group of photographs (as in a book or magazine) arranged to explore a theme or tell a story

pho·to·ex·ci·ta·tion [,fō-tō-,ek-,sī-'tā-shən, -,ek-sə-] -n, adj

  1. the process of exciting the atoms or molecules of a substance by the absorption of radiant energy

photo finish -n

  1. a race or finish in which contestants are so close that a photograph of them as they cross the finish line has to be examined to determine the winner
  2. a close contest

pho·to·fin·ish·er [,fō-tō-'fi-ni-shər] -n

  1. one that develops and prints photographic film commercially

pho·to·flash ['fō-tō-,flash] -n

  1. flash

pho·to·flood [-,fləd] -n

  1. an electric lamp that provides intense sustained illumination for taking photographs

pho·tog [fə-'täg] -n

  1. one who takes photographs : photographer

pho·to·ge·nic [,fō-tə-'je-nik, -'jē-] -adj, adv

  1. produced or precipitated by light
    • photogenic dermatitis
  2. producing or generating light : phosphorescent
    • photogenic bacteria
  3. suitable for being photographed esp. because of visual appeal
    • a photogenic smile

pho·to·ge·ol·o·gy [,fō-tō-jē-'ä-lə-jē] -n, adj

  1. a branch of geology concerned with the identification and study of geological features through the study of aerial or orbital photographs

pho·to·gram ['fō-tə-,gram] -n

  1. a shadowlike photograph made by placing objects between light-sensitive paper and a light source

pho·to·gram·me·try [,fō-tə-'gra-mə-trē] -n, adj

  1. the science of making reliable measurements by the use of photographs and esp. aerial photographs (as in surveying)

pho·to·graph ['fō-tə-,graf] -n

  1. a picture or likeness obtained by photography

photograph -vt

  1. to take a photograph of
  2. to take a photograph
  3. to appear as an image in a photograph
    • an actress who photograph s well

pho·tog·ra·pher [fə-'tä-grə-fər] -n

  1. one who practices photography
  2. one who makes a business of taking photographs

pho·to·graph·ic [,fō-tə-'gra-fik] -adj, adv

  1. relating to, obtained by, or used in photography
  2. representing nature and human beings with the exactness of a photograph
  3. capable of retaining vivid impressions
    • a photographic memory

pho·tog·ra·phy [fə-'tä-grə-fē] -n

  1. the art or process of producing images by the action of radiant energy and esp. light on a sensitive surface (as film or a CCD chip)

pho·to·gra·vure [,fō-tə-grə-'vyu̇r] -n

  1. a process for printing from an intaglio plate prepared by photographic methods

pho·to·in·duced [,fō-tō-in-'düst, -'dyüst] -adj, n

  1. induced by the action of light

pho·to·in·ter·pre·ta·tion [-in-,tər-prə-'tā-shən, -pə-] -n

  1. the science of identifying and describing objects in photographs

pho·to·ion·i·za·tion [-,ī-ə-nə-'zā-shən] -n, vt

  1. ionization (as in the ionosphere) of a molecule or atom caused by absorption of radiant energy

pho·to·jour·nal·ism [,fō-tō-'jər-nə-,li-zəm] -n, adj

  1. journalism in which written copy is subordinate to pictorial usu. photographic presentation of news stories or in which a high proportion of pictorial presentation is used
  2. news photography

pho·to·ki·ne·sis [-kə-'nē-səs, -kī-] -n, adj

  1. motion or activity induced by light

pho·to·li·thog·ra·phy [-li-'thä-grə-fē] -n, n or vt, adj, adv

  1. lithography in which photographically prepared plates are used
  2. a process involving the photographic transfer of a pattern to a surface for etching (as in producing an integrated circuit)

pho·tol·y·sis [fō-'tä-lə-səs] -n, adj, adv

  1. chemical decomposition by the action of radiant energy (as light)

pho·to·lyze ['fō-tə-,līz] -vt, adj

  1. to cause to undergo photolysis

pho·to·map ['fō-tō-,map] -n, vb

  1. a photograph which is taken vertically from above (as from an airplane) and upon which a grid and data pertinent to maps have been added

pho·to·mask [-,mask] -n

  1. mask

pho·to·me·chan·i·cal [,fō-tō-mi-'ka-ni-kəl] -adj, adv

  1. relating to or involving any of various processes for producing printed matter from a photographically prepared surface

pho·tom·e·ter [fō-'tä-mə-tər] -n

  1. an instrument for measuring luminous intensity, luminous flux, illumination, or brightness

pho·to·met·ric [,fō-tə-'me-trik] -adj, adv

  1. of or relating to photometry or the photometer

pho·tom·e·try [fō-'tä-mə-trē] -n

  1. a branch of science that deals with measurement of the intensity of light
  2. the practice of using a photometer

pho·to·mi·cro·graph [,fō-tə-'mī-krə-,graf] -n, adj

  1. a photograph of a microscope image

pho·to·mon·tage [-män-'täzh, -mōⁿ(n)-] -n

  1. montage using photographic images
  2. a picture made by photomontage

pho·to·mor·pho·gen·e·sis [,fō-tə-,mȯr-fə-'je-nə-səs] -n, adj

  1. plant morphogenesis controlled by radiant energy (as light)

pho·to·mo·sa·ic [-mō-'zā-ik] -n

  1. an image composed of many smaller photographs
  2. mosaic

pho·to·mul·ti·pli·er tube [,fō-tō-'məl-tə-,plī(-ə)r-] -n

  1. a vacuum tube that detects light esp. from dim sources through the use of photoemission and successive instances of secondary emission to produce enough electrons to generate a useful current called also photomultiplier

pho·to·mu·ral [-'myu̇r-əl] -n

  1. an enlarged photograph usu. several yards long used on walls esp. as decoration

pho·ton ['fō-,tän] -n, adj

  1. a unit of intensity of light at the retina equal to the illumination received per square millimeter of a pupillary area from a surface having a brightness of one candle per square meter
  2. a quantum of electromagnetic radiation

pho·to·neg·a·tive [,fō-tō-'ne-gə-tiv] -adj

  1. exhibiting negative phototropism or phototaxis

pho·ton·ics [fō-'tä-niks] -n pl but sing in constr

  1. a branch of physics that deals with the properties and applications of photons esp. as a medium for transmitting information

pho·to·nu·cle·ar [,fō-tō-'nü-klē-ər, -'nyü-, ÷-kyə-lər] -adj

  1. relating to or caused by the incidence of radiant energy (as gamma rays) on atomic nuclei

pho·tooff·set [-'ȯf-,set] -n

  1. offset printing from photolithographic plates

photo op [-'äp] -n

  1. photo opportunity

photo opportunity -n

  1. a situation or event that lends itself to and is often arranged expressly for the taking of pictures that give favorable publicity to the individuals photographed

pho·to·ox·i·da·tion [-,äk-sə-'dā-shən] -n, adj, vb

  1. oxidation under the influence of radiant energy (as light)

pho·to·pe·ri·od [-'pir-ē-əd] -n, adj, adv

  1. a recurring cycle of light and dark periods of constant length
  2. photophase

pho·to·pe·ri·od·ism [-'pir-ē-ə-,di-zəm] -n

  1. a plant or animal's response or capacity to respond to photoperiod

pho·to·phase ['fō-tə-,fāz] -n

  1. light reaction
  2. the light period of a photoperiodic cycle of light and dark

pho·to·pho·bia [,fō-tə-'fō-bē-ə] -n

  1. intolerance to light
  2. painful sensitiveness to strong light

pho·to·pho·bic [-'fō-bik] -adj

  1. shunning or avoiding light
  2. growing best under reduced illumination
  3. of or relating to photophobia

pho·to·phore ['fō-tə-,fȯr] -n

  1. a light-emitting organ
  2. one of the luminous spots on various marine mostly deep-sea fishes

pho·to·phos·phor·y·la·tion ['fō-tō-,fäs-,fȯr-ə-'lā-shən] -n

  1. the synthesis of ATP from ADP and phosphate that occurs in a plant using radiant energy absorbed during photosynthesis

phot·opic [fōt-'ō-pik, -'ä-pik] -adj

  1. relating to or being vision in bright light with light-adapted eyes that is mediated by the cones of the retina

pho·to·play ['fō-tō-,plā] -n

  1. motion picture

pho·to·po·la·rim·e·ter [,fō-tō-,pō-lə-'ri-mə-tər] -n

  1. an instrument used to measure the intensity and polarization of reflected light (as from clouds enveloping a planet)

pho·to·poly·mer [,fō-tō-'pä-lə-mər] -n

  1. a photosensitive plastic used esp. in the manufacture of printing plates

pho·to·pos·i·tive [-'pä-zə-tiv, -'päz-tiv] -adj

  1. exhibiting positive phototropism or phototaxis

pho·to·prod·uct [-'prä-(,)dəkt] -n

  1. a product of a photochemical reaction

pho·to·re·ac·tion [-rē-'ak-shən] -n

  1. a photochemical reaction

pho·to·re·ac·ti·va·tion [-rē-,ak-tə-'vā-shən] -n, adj

  1. repair of DNA (as of a bacterium) esp. by a light-dependent enzymatic reaction after damage by ultraviolet irradiation

pho·tore·al·ism [,fō-tō-'rē-ə-,li-zəm] -n, n or adj, adj

  1. realism in painting characterized by extremely meticulous depiction of detail

pho·to·re·cep·tion [-ri-'sep-shən] -n, adj

  1. perception of waves in the range of visible light
  2. vision

pho·to·re·cep·tor [-'sep-tər] -n

  1. a receptor for light stimuli

pho·to·re·con·nais·sance [-ri-'kä-nə-zən(t)s also -sən(t)s] -n

  1. reconnaissance in which aerial photographs are taken

pho·to·re·duc·tion [-ri-'dək-shən] -n, vt

  1. chemical reduction under the influence of radiant energy (as light) : photochemical reduction

pho·to·re·frac·tive ker·a·tec·to·my [,fō-tō-ri-,frak-tiv-,ker-ə-'tek-tə-mē] -n

  1. surgical removal of part of the corneal surface using an excimer laser in order to correct for myopia

pho·to·re·pro·duc·tion [-,rē-prə-'dək-shən] -n

  1. reproduction by photographic means
  2. photocopy

pho·to·re·sist ['fō-tō-ri-,zist, ,fō-tō-ri-'] -n

  1. a photosensitive resin that loses its resistance to chemical etching when exposed to radiation and is used esp. in the transference of a circuit pattern to a semiconductor chip during the production of an integrated circuit

pho·to·res·pi·ra·tion [,fō-tō-,res-pə-'rā-shən] -n

  1. a light-dependent process in some higher plants resulting in the oxidation of glycolic acid and release of carbon dioxide that under some environmental conditions (as high temperature) tends to inhibit photosynthesis

pho·to·sen·si·tive [-'sen(t)-s(ə-)tiv] -adj, n

  1. sensitive to the action of radiant energy
    • photosensitive paper
  2. being or caused by an abnormal reaction to sunlight
    • photosensitive rashes

pho·to·sen·si·ti·za·tion [-,sen(t)-s(ə-)tə-'zā-shən] -n

  1. the process of photosensitizing
  2. the condition of being photosensitized
  3. the development of an abnormal capacity to react to sunlight typically by edematous swelling and dermatitis

pho·to·sen·si·tize [-'sen(t)-sə-,tīz] -vt, n

  1. to sensitize to the influence of radiant energy and esp. light

pho·to·set ['fō-tō-,set] -vt, n

  1. photocompose

pho·to·shop ['fō-(,)tō-,shäp] -vt

  1. to alter (as a digital image) with computer software

pho·to·sphere ['fō-tə-,sfir] -n, adj

  1. a sphere of light or radiance
  2. the luminous surface layer of the sun or a star

pho·to·stat ['fō-tə-,stat] -n

  1. a device for making a photographic copy of graphic matter
  2. a copy made by this device

photostat -vt

  1. to copy by a photostat

pho·to·stat·ic [,fō-tə-'sta-tik] -adj

  1. of, made by, or using a photostat
    • a photostatic copy
    • a photostatic process

pho·to·syn·thate [,fō-tō-'sin-,thāt] -n

  1. a product of photosynthesis

pho·to·syn·the·sis [-'sin(t)-thə-səs] -n, vi, adj, adv

  1. synthesis of chemical compounds with the aid of radiant energy and esp. light
  2. formation of carbohydrates from carbon dioxide and a source of hydrogen (as water) in the chlorophyll-containing tissues of plants exposed to light

pho·to·sys·tem ['fō-tō-,sis-təm] -n

  1. : either of two photochemical reaction centers consisting chiefly of photosynthetic pigments complexed with protein and occurring in chloroplasts:
  2. one that absorbs light with a wavelength of about 700 nanometers called also photosystem I
  3. one that absorbs light with a wavelength of about 680 nanometers called also photosystem II

pho·to·tac·tic [,fō-tō-'tak-tik] -adj, adv

  1. of, relating to, or exhibiting phototaxis

pho·to·tax·is [-'tak-səs] -n

  1. a taxis in which light is the directive factor

pho·to·te·leg·ra·phy [-tə-'le-grə-fē] -n

  1. facsimile

pho·to·ther·a·py [,fō-tō-'ther-ə-pē] -n

  1. light therapy

pho·to·tox·ic [-'täk-sik] -adj, n

  1. rendering the skin susceptible to damage (as sunburn or blisters) upon exposure to light and esp. ultraviolet light
    • phototoxic antibiotics
  2. induced by a phototoxic substance

pho·to·tran·sis·tor [-tran-'zis-tər, -tran(t)-'sis-] -n

  1. a photoconductive semiconductor device used esp. as a photodetector

pho·to·tro·pic [,fō-tə-'trō-pik, -'trä-] -adj, adv

  1. of, relating to, or capable of phototropism

pho·tot·ro·pism [fō-'tä-trə-,pi-zəm] -n

  1. a tropism in which light is the orienting stimulus

pho·to·tube ['fō-tō-,tüb, -,tyüb] -n

  1. an electron tube having a photoemissive cathode whose released electrons are drawn to the anode by reason of its positive potential

pho·to·type·set·ting [,fō-tō-'tīp-,se-tiŋ] -n

  1. photocomposition
  2. photocomposition done on a keyboard or tape-operated composing machine

pho·to·vol·ta·ic [-väl-'tā-ik, -vōl-] -adj, n

  1. of, relating to, or utilizing the generation of a voltage when radiant energy falls on the boundary between dissimilar substances (as two different semiconductors)

phr -abbr

  1. phrase

phrag·mi·tes [frag-'mī-,tēz] -n

  1. any of a genus ( Phragmites) of widely distributed reeds with tall stems and large showy panicles resembling plumes

phrag·mo·plast ['frag-mō-,plast] -n

  1. the enlarged barrel-shaped spindle that is characteristic of the later stages of plant mitosis and within which the cell plate forms

phras·al ['frā-zəl] -adj, adv

  1. of, relating to, or consisting of a phrase
    • phrasal prepositions

phrase ['frāz] -n

  1. a characteristic manner or style of expression : diction
  2. a brief expression
  3. catchphrase
  4. word
  5. a short musical thought typically two to four measures long closing with a cadence
  6. a word or group of words forming a syntactic constituent with a single grammatical function
    • an adverbial phrase
  7. a series of dance movements comprising a section of a pattern
  8. to express in words or in appropriate or telling terms
  9. to designate by a descriptive word or phrase
  10. to divide into melodic phrases

phrase book -n

  1. a book containing idiomatic expressions of a foreign language and their translation

phrase·mak·er ['frāz-,mā-kər] -n

  1. one who coins impressive phrases
  2. one given to making fine-sounding but often hollow and meaningless phrases

phrase·mon·ger [-,məŋ-gər, -,mäŋ-] -n

  1. phrasemaker

phra·se·o·log·i·cal [,frā-zē-ə-'lä-ji-kəl] -adj

  1. expressed in formal often sententious phrases
  2. marked by frequently insincere use of such phrases
  3. of or relating to phraseology

phra·se·ol·o·gist [,frā-zē-'ä-lə-jist, frā-'zä-] -n

  1. one who uses sententious or insincere phrases

phra·se·ol·o·gy [-jē] -n

  1. a manner of organizing words and phrases into longer elements : style
  2. choice of words

phrasing -n

  1. style of expression : phraseology
  2. the act, method, or result of grouping notes into musical phrases

phra·try ['frā-trē] -n

  1. a kinship group forming a subdivision of a Greek phyle
  2. a tribal subdivision
  3. an exogamous group typically comprising several totemic clans

phreak ['frēk] -n

  1. phreaker

phreak·er ['frē-kər] -n

  1. one who gains illegal access to the telephone system

phre·at·ic [frē-'a-tik] -adj

  1. of, relating to, or being groundwater
  2. of, relating to, or being an explosion caused by steam derived from groundwater

phre·at·o·phyte [frē-'a-tə-,fīt] -n, adj

  1. a deep-rooted plant that obtains its water from the water table or the layer of soil just above it

phre·net·ic [fri-'ne-tik] -adj, adv, n

(variant of frenetic)

  1. frenzied, frantic

phren·ic ['fre-nik] -adj

  1. of or relating to the diaphragm
  2. of or relating to the mind

phre·nol·o·gy [fri-'nä-lə-jē] -n, adj

  1. the study of the conformation of the skull based on the belief that it is indicative of mental faculties and character

phren·sy ['fren-zē] -n

(variant of frenzy)

  1. a temporary madness
  2. a violent mental or emotional agitation
  3. intense usu. wild and often disorderly compulsive or agitated activity
    • a shopping frenzy

Phry·gian ['fri-j(ē-)ən] -n, adj

  1. a native or inhabitant of ancient Phrygia
  2. the extinct Indo-European language of the Phrygians

phthal·ate ['tha-,lāt] -n

  1. any of various salts or esters of phthalic acid used esp. as plasticizers and in solvents

phthal·ic acid ['tha-lik-] -n

  1. any of three isomeric acids C 8H 6O 4obtained by oxidation of various benzene derivatives

phthalic anhydride -n

  1. a crystalline cyclic acid anhydride C 8H 4O 3used esp. in making alkyd resins

phtha·lo·cy·a·nine [,tha-lō-'sī-ə-,nēn, ,thā-] -n

  1. a bright greenish-blue crystalline compound C 32H 18N 8
  2. any of several metal derivatives that are brilliant fast blue to green dyes or pigments

phthis·ic ['ti-zik] -n, adj

  1. phthisis

phthi·sis ['thī-səs, 'tī-, 'thi-, 'ti-] -n

  1. a progressively wasting or consumptive condition
  2. pulmonary tuberculosis

phyco- -comb form

  1. algae
    • phyco logy

phy·co·cy·a·nin [,fī-kō-'sī-ə-nən] -n

  1. any of various bluish-green protein pigments in the cells of cyanobacteria

phy·co·er·y·thrin [-'er-i-thrən] -n

  1. any of the red protein pigments in the cells of red algae

phy·col·o·gy [fī-'kä-lə-jē] -n, adj

  1. the study or science of algae called also algology

phy·co·my·cete [,fī-kō-'mī-,sēt, -,mī-'sēt] -n, adj

  1. any of a large class (Phycomycetes) of lower fungi that are in many respects similar to algae and are now often assigned to subdivisions (as Mastigomycotina and Zygomycota)

phyl- -comb form

  1. tribe : race : phylum
    • phylo geny

phy·lac·tery [fə-'lak-t(ə-)rē] -n

  1. either of two small square leather boxes containing slips inscribed with scriptural passages and traditionally worn on the left arm and on the head by observant Jewish men and esp. adherents of Orthodox Judaism during morning weekday prayers
  2. amulet

phy·le ['fī-(,)lē] -n

  1. the largest political subdivision among the ancient Athenians

phy·let·ic [fī-'le-tik] -adj, adv

  1. of or relating to evolutionary change in a single line of descent without branching

phyll- -comb form

  1. leaf
    • phyll ome

phyl·la·ry ['fi-lə-rē] -n

  1. one of the involucral bracts subtending the flower head of a composite plant

phyl·lo ['fē-(,)lō, 'fī-] -n

  1. extremely thin dough that is layered to produce a flaky pastry

phyl·lo·clade ['fi-lə-,klād] -n

  1. a flattened stem or branch (as a joint of a cactus) that functions as a leaf

phyl·lode ['fi-,lōd] -n

  1. a flat expanded petiole that replaces the blade of a foliage leaf, fulfills the same functions, and is analogous to a cladophyll

phyl·lome ['fi-,lōm] -n

  1. a plant part that is a leaf or is phylogenetically derived from a leaf

phyl·lo·tac·tic [,fi-lə-'tak-tik] -adj

  1. of or relating to phyllotaxis

phyl·lo·tax·is [,fi-lə-'tak-səs] -n

  1. the arrangement of leaves on a stem and in relation to one another
  2. the study of phyllotaxis and of the laws that govern it

phyl·lox·e·ra [,fi-,läk-'sir-ə, fə-'läk-sə-rə] -n

  1. any of several plant lice (family Phylloxeridae)
  2. one ( Daktulosphaira vitifoliaesyn. Viteus vitifoliae) orig. of No. America but introduced into Europe and elsewhere that produces galls on the leaves and roots of grape vines and is a serious pest esp. of vinifera grapes in wine-producing regions

phy·lo·ge·net·ic [,fī-lō-jə-'ne-tik] -adj, adv

  1. of or relating to phylogeny
  2. based on natural evolutionary relationships
  3. acquired in the course of phylogenetic development : racial

phy·log·e·ny [fī-'lä-jə-nē] -n

  1. the evolutionary history of a kind of organism
  2. the evolution of a genetically related group of organisms as distinguished from the development of the individual organism
  3. the history or course of the development of something (as a word or custom)

phy·lum ['fī-ləm] -n

  1. a direct line of descent within a group
  2. a group that constitutes or has the unity of a phylum
  3. a primary category in biological taxonomy esp. of animals that ranks above the class and below the kingdom
  4. a group of languages related more remotely than those of a family or stock

phys -abbr

  1. physical
  2. physics

phys ed ['fiz-'ed] -n

  1. physical education

physi- -comb form

  1. nature
    • physio graphy
  2. physical
    • physio therapy

phys·iat·rist [,fi-zē-'a-trist] -n

  1. a physician who specializes in physiatry

phys·iat·ry [,fi-zē-'a-trē, fə-'zī-ə-trē] -n

  1. physical medicine and rehabilitation

phys·ic ['fi-zik] -n

  1. the art or practice of healing disease
  2. the practice or profession of medicine
  3. a medicinal agent or preparation
  4. purgative
  5. natural science

physic -vt

  1. to treat with or administer medicine to
  2. purge
  3. heal, cure

phys·i·cal ['fi-zi-kəl] -adj, adv, n

  1. of or relating to natural science
  2. of or relating to physics
  3. characterized or produced by the forces and operations of physics
  4. having material existence : perceptible esp. through the senses and subject to the laws of nature
    • everything physical is measurable by weight, motion, and resistance -- Thomas De Quincey
  5. of or relating to material things
  6. of or relating to the body
    • physical abuse
  7. concerned or preoccupied with the body and its needs : carnal
    • physical appetites
  8. sexual
    • a physical love affair
    • physical attraction
  9. characterized by esp. rugged and forceful physical activity : rough
    • a physical hockey game
    • a physical player

physical -n

  1. physical examination

physical anthropology -n

  1. anthropology concerned with the comparative study of human evolution, variation, and classification esp. through measurement and observation

physical education -n

  1. instruction in the development and care of the body ranging from simple calisthenic exercises to a course of study providing training in hygiene, gymnastics, and the performance and management of athletic games

physical examination -n

  1. an examination of the bodily functions and condition of an individual

physical geography -n

  1. geography that deals with the exterior physical features and changes of the earth

phys·i·cal·ism ['fi-zi-kə-,li-zəm] -n, n or adj, adj

  1. a thesis that the descriptive terms of scientific language are reducible to terms which refer to spatiotemporal things or events or to their properties

phys·i·cal·i·ty [,fi-zə-'ka-lə-tē] -n

  1. intensely physical orientation : predominance of the physical usu. at the expense of the mental, spiritual, or social
  2. a physical aspect or quality

phys·i·cal·ize ['fi-zi-kə-,līz] -vt

  1. to give physical form or expression to
    • her gestures physicalized her major points

physical medicine and rehabilitation -n

  1. a medical specialty concerned with treating disabling disorders and injuries by physical means (as by the use of electrotherapy, therapeutic exercise, or pharmaceutical pain control) called also physiatry physical medicine

physical science -n

  1. any of the natural sciences (as physics, chemistry, and astronomy) that deal primarily with nonliving materials

physical therapy -n

  1. the treatment of disease, injury, or disability by physical and mechanical means (as massage, regulated exercise, water, light, heat, and electricity)

phy·si·cian [fə-'zi-shən] -n

  1. a person skilled in the art of healing
  2. one educated, clinically experienced, and licensed to practice medicine as usu. distinguished from surgery
  3. one exerting a remedial or salutary influence

physician assistant -n

  1. a person certified to provide basic medical services usu. under the supervision of a licensed physician called also PA physician's assistant

physicianassisted suicide -n

  1. suicide by a patient facilitated by means (as a drug prescription) or by information (as an indication of a lethal dosage) provided by a physician aware of the patient's intent

physician's assistant -n

  1. a person certified to provide basic medical services usu. under the supervision of a licensed physician called also PA physician assistant

phys·i·cist ['fi-zə-sist, 'fiz-sist] -n

  1. a specialist in physics
  2. a person skilled in natural science

phys·i·co·chem·i·cal [,fi-zi-kō-'ke-mi-kəl] -adj, adv

  1. being physical and chemical
  2. of or relating to chemistry that deals with the physicochemical properties of substances

phys·ics ['fi-ziks] -n pl but sing or pl in constr

  1. a science that deals with matter and energy and their interactions
  2. the physical processes and phenomena of a particular system
  3. the physical properties and composition of something

phys·io·crat ['fi-zē-ə-,krat] -n, adj

  1. a member of a school of political economists founded in 18th century France and characterized chiefly by a belief that government policy should not interfere with the operation of natural economic laws and that land is the source of all wealth

phys·i·og·nom·ic [,fi-zē-ə(g)-'nä-mik] -adj, adv

  1. of, relating to, or characteristic of physiognomy or the physiognomy

phys·i·og·no·my [,fi-zē-'ä(g)-nə-mē] -n

  1. the art of discovering temperament and character from outward appearance
  2. the facial features held to show qualities of mind or character by their configuration or expression
  3. external aspect
  4. inner character or quality revealed outwardly

phys·i·og·ra·phy [,fi-zē-'ä-grə-fē] -n, adj

  1. physical geography

physiol -abbr

  1. physiologist; physiology

phys·i·o·log·i·cal [,fi-zē-ə-'lä-ji-kəl] -adj, adv

  1. of or relating to physiology
  2. characteristic of or appropriate to an organism's healthy or normal functioning
    • the sodium level was physiological
  3. differing in, involving, or affecting physiological factors
    • a physiological strain of bacteria

physiological psychology -n

  1. a branch of psychology that deals with the effects of normal and pathological physiological processes on mental life called also psychophysiology

physiological saline -n

  1. a solution of a salt or salts that is essentially isotonic with tissue fluids or blood

phys·i·ol·o·gy [,fi-zē-'ä-lə-jē] -n

  1. a branch of biology that deals with the functions and activities of life or of living matter (as organs, tissues, or cells) and of the physical and chemical phenomena involved
  2. the organic processes and phenomena of an organism or any of its parts or of a particular bodily process

phys·io·pa·thol·o·gy ['fi-zē-ō-pə-'thä-lə-jē, -pa-] -n, adj

  1. a branch of biology or medicine that combines physiology and pathology esp. in the study of altered bodily function in disease

phys·io·ther·a·py [,fi-zē-ō-'ther-ə-pē] -n

  1. physical therapy

phy·sique [fə-'zēk] -n

  1. the form or structure of a person's body : bodily makeup

phy·so·stig·mine [,fī-sə-'stig-,mēn] -n

  1. a crystalline tasteless alkaloid C 15H 21N 3O 2from the Calabar bean that is used in medicine esp. in the form of its salicylate for its anticholinesterase activity

phyt- -comb form

  1. plant
    • phyto phagous

phy·tane ['fī-,tān] -n

  1. an isoprenoid hydrocarbon C 20H 42that is found esp. associated with fossilized plant remains from the Precambrian and later eras

phy·to·alex·in [,fī-tō-ə-'lek-sən] -n

  1. any of various antimicrobial chemical substances produced by plants to combat infection by a pathogen (as a fungus)

phy·to·chem·i·cal [-'ke-mi-kəl] -adj, adv

  1. of, relating to, or being phytochemistry

phytochemical -n

  1. a chemical compound (as beta-carotene) occurring naturally in plants

phy·to·chem·is·try [-'ke-mə-strē] -n

  1. the chemistry of plants, plant processes, and plant products

phy·to·chrome ['fī-tə-,krōm] -n

  1. any of a group of proteins bound to light-absorbing pigments in many plants that play a role in initiating floral and developmental processes when activated by red or near-infrared radiation

phy·to·es·tro·gen [,fī-tō-'es-trə-jən] -n

  1. a chemical compound (as genistein) that occurs naturally in plants and has estrogenic properties

phy·to·fla·gel·late [,fī-tō-'fla-jə-lət, -,lāt; -flə-'je-] -n

  1. any of various organisms (as dinoflagellates) that are considered a subclass (Phytomastigophora syn. Phytomastigina) usu. of algae by botanists and of protozoans by zoologists and that have many characteristics in common with typical algae

phy·to·ge·og·ra·phy [,fī-tō-jē-'ä-grə-fē] -n, adj, adv

  1. the biogeography of plants

phy·to·he·mag·glu·ti·nin [-,hē-mə-'glü-tə-nən] -n

  1. a proteinaceous hemagglutinin of plant origin used esp. to induce mitosis (as in lymphocytes)

phy·to·hor·mone [-'hȯr-,mōn] -n

  1. plant hormone

phy·to·lith ['fī-tə-,lith] -n

  1. a microscopic siliceous particle that is formed by a plant and that is highly resistant to decomposition
    • ancient vegetation revealed by phytolith s

phy·ton ['fī-,tän] -n, adj

  1. a structural unit of a plant consisting of a leaf and its associated portion of stem
  2. the smallest part of a stem, root, or leaf that when severed may grow into a new plant

phy·to·nu·tri·ent [,fī-tō-'nü-trē-ənt, -'nyü-] -n

  1. a bioactive plant-derived compound (as resveratrol) associated with positive health effects

phy·to·path·o·gen [,fī-tō-'pa-thə-jən] -n, adj

  1. an organism parasitic on a plant host

phy·to·pa·thol·o·gy [-pə-'thä-lə-jē, -pa-] -n, adj

  1. plant pathology

phy·toph·a·gous [fī-'tä-fə-gəs] -adj

  1. feeding on plants

phy·to·plank·ter [,fī-tō-'plaŋ(k)-tər] -n

  1. a planktonic plant

phy·to·plank·ton [-'plaŋ(k)-tən, -,tän] -n, adj

  1. planktonic plant life

phy·to·plas·ma [,fī-tə-'plaz-mə] -n

  1. any of a group of bacteria that are related to mycoplasmas, cause plant diseases (as aster yellows) by infecting phloem tissue, are transmitted esp. by homopteran insect vectors, and have proved extremely difficult to grow in artificial media called also mycoplasma-like organism

phy·to·so·ci·ol·o·gy [-,sō-sē-'ä-lə-jē, -shē-] -n, adj

  1. a branch of ecology concerned esp. with the structure, composition, and interrelationships of plant communities

phy·tos·ter·ol [fī-'täs-tə-,rȯl, -,rōl] -n

  1. any of various sterols derived from plants

phy·to·tox·ic [,fī-tə-'täk-sik] -adj, n

  1. poisonous to plants