ap -abbr

  1. apostle
  2. apothecaries'

AP -abbr

  1. additional premium
  2. adjective phrase
  3. airplane
  4. American plan
  5. antipersonnel
  6. arithmetic progression
  7. armorpiercing
  8. Associated Press
  9. author's proof

apace [ə-'pās] -adv

  1. at a quick pace : swiftly
    • growing apace
  2. abreast used with of or with
    • trying to keep apace with changes in technology

Apache [ə-'pa-chē, in sense 3 ə-'pash] -n, adj or n

  1. a member of a group of American Indian peoples of the southwestern U.S.
  2. any of the Athabascan languages of the Apache people
  3. a member of a gang of criminals esp. in Paris
  4. ruffian

apanage ['a-pə-nij] -n

(variant of appanage)

  1. a grant (as of land or revenue) made by a sovereign or a legislative body to a dependent member of the royal family or a principal vassal
  2. a property or privilege appropriated to or by a person as something due
  3. a rightful endowment or adjunct

ap·a·re·jo [,a-pə-'rā-(,)(h)ō] -n

  1. a packsaddle of stuffed leather or canvas

apart [ə-'pärt] -adv

  1. at a little distance
    • tried to keep apart from the family squabbles
  2. away from one another in space or time
    • towns 20 miles apart
  3. as a separate unit : independently
    • viewed apart, his arguments were unsound
  4. so as to separate one from another
    • found it hard to tell the twins apart
  5. excluded from consideration : aside
    • a few blemishes apart, the novel is excellent
  6. in or into two or more parts : to pieces
    • coming apart at the seams
  7. separate, isolated
    • those athletes are a breed apart
  8. holding different opinions : divided

apart from -prep

  1. other than : besides, except for

apart·heid [ə-'pär-,tāt, -,tīt] -n

  1. racial segregation
  2. a former policy of segregation and political and economic discrimination against non-European groups in the Republic of So. Africa
  3. separation, segregation
    • cultural apartheid
    • gender apartheid

apart·ment [ə-'pärt-mənt] -n, adj

  1. a room or set of rooms fitted esp. with housekeeping facilities and usu. leased as a dwelling
  2. a building containing several individual apartments

apartment building -n

  1. a building containing separate residential apartments called also apartment house

apartment hotel -n

  1. a hotel containing apartments as well as accommodations for transients

ap·a·thet·ic [,a-pə-'the-tik] -adj, adv

  1. having or showing little or no feeling or emotion : spiritless
  2. having little or no interest or concern : indifferent

ap·a·thy ['a-pə-thē] -n

  1. lack of feeling or emotion : impassiveness
  2. lack of interest or concern : indifference

ap·a·tite ['a-pə-,tīt] -n

  1. any of a group of calcium phosphate minerals occurring in various colors as hexagonal crystals, as granular masses, or in fine-grained masses as the chief constituent of phosphate rock and of bones and teeth
  2. calcium phosphate fluoride

apato·sau·rus [ə-,pa-tə-'sȯr-əs] -n

  1. brontosaurus

APB -abbr

  1. all points bulletin

APC [,ā-(,)pē-'sē] -n

  1. an armored vehicle used to transport military personnel

ape ['āp] -n, adj

  1. monkey
  2. one of the larger tailless or short-tailed Old World forms
  3. any of two families (Pongidae and Hylobatidae) of large tailless semierect primates (as the chimpanzee, gorilla, orangutan, or gibbon) called also anthropoid anthropoid ape
  4. mimic
  5. a large uncouth person
  6. to copy closely but often clumsily and ineptly
  7. crazy, wild usu. used in the phrase go ape

apeak [ə-'pēk] -adj or adv

  1. being in a vertical position
    • with oars apeak

apeman ['āp-,man, -'man] -n

  1. a primate (as an australopithecine) intermediate in character between Homo sapiens and the higher apes

aper·u [,a-pər-'sü] -n

  1. a brief survey or sketch : outline
  2. an immediate impression
  3. insight

ape·ri·ent [ə-'pir-ē-ənt] -adj, n

  1. gently moving the bowels : laxative

ape·ri·od·ic [,ā-,pir-ē-'ä-dik] -adj, adv, n

  1. of irregular occurrence : not periodic
    • aperiodic floods
  2. not having periodic vibrations : not oscillatory

aper·i·tif [ə-,per-ə-'tēf, a-; ,ä-pər-(ə-)'tēf] -n

  1. an alcoholic drink taken before a meal as an appetizer

ap·er·ture ['ap-ə(r)-,chu̇r, -chər, -,tyu̇r, -,tu̇r] -n

  1. an opening or open space : hole
  2. the opening in a photographic lens that admits the light
  3. the diameter of the stop in an optical system that determines the diameter of the bundle of rays traversing the instrument
  4. the diameter of the objective lens or mirror of a telescope

apet·al·ous [(,)ā-'pe-tᵊl-əs] -adj

  1. having no petals

apex ['ā-,peks] -n

  1. the uppermost point : vertex
    • the apex of a mountain
  2. the narrowed or pointed end : tip
    • the apex of the tongue
  3. the highest or culminating point
    • the apex of his career

Ap·gar score ['ap-,gär-] -n

  1. an index used to evaluate the condition of a newborn infant based on a rating of 0, 1, or 2 for each of the five characteristics of color, heart rate, response to stimulation of the sole of the foot, muscle tone, and respiration with 10 being a perfect score

aphaer·e·sis [ə-'fer-ə-səs] -n, adj

  1. the loss of one or more sounds or letters at the beginning of a word (as in roundfor aroundand coonfor raccoon)

apha·sia [ə-'fā-zh(ē-)ə] -n, n or adj

  1. loss or impairment of the power to use or comprehend words usu. resulting from brain damage

aph·elion [a-'fēl-yən, ,ap-'hēl-] -n

  1. the point in the path of a celestial body (as a planet) that is farthest from the sun

aphe·re·sis [,a-fə-'rē-səs] -n, pl

  1. withdrawal of blood from a donor's body, removal of one or more blood components (as plasma, platelets, or white blood cells), and transfusion of the remaining blood back into the donor called also pheresis

aph·e·sis ['a-fə-səs] -n, adj, adv

  1. aphaeresis consisting of the loss of a short unaccented vowel (as in lonefor alone)

aphid ['ā-fəd also 'a-fəd] -n

  1. any of numerous very small soft-bodied homopterous insects (superfamily Aphidoidea) that suck the juices of plants

aphid lion -n

  1. any of several insect larvae (as a lacewing or ladybug larva) that feed on aphids called also aphis lion

aphis ['ā-fəs also 'a-fəs] -n

  1. any of a genus ( Aphis) of aphids
  2. aphid

apho·nia [(,)ā-'fō-nē-ə] -n, adj

  1. loss of voice and of all but whispered speech

aph·o·rism ['a-fə-,ri-zəm] -n, adj, adv

  1. a concise statement of a principle
  2. a terse formulation of a truth or sentiment : adage

aph·o·rize ['a-fə-,rīz] -vi

  1. to write or speak in or as if in aphorisms

apho·tic [(,)ā-'fō-tik] -adj

  1. being the deep zone of an ocean or lake receiving too little light to permit photosynthesis

aph·ro·di·si·ac [,a-frə-'dē-zē-,ak, -'di-zē-] -n, adj

  1. an agent (as a food or drug) that arouses or is held to arouse sexual desire
  2. something that excites

Aph·ro·di·te [,a-frə-'dī-tē] -n

  1. the Greek goddess of love and beauty

api·ar·i·an [,ā-pē-'er-ē-ən] -adj

  1. of or relating to beekeeping or bees

api·a·rist ['ā-pē-ə-rist, -pē-,er-ist] -n

  1. beekeeper

api·ary ['ā-pē-,er-ē, -,e-rē] -n

  1. a place where bees are kept
  2. a collection of hives or colonies of bees kept for their honey

api·cal ['ā-pi-kəl also 'a-pi-] -adj, adv

  1. of, relating to, or situated at an apex
  2. of, relating to, or formed with the tip of the tongue
    • n, l, and r are apical consonants

apical dominance -n

  1. inhibition of the growth of lateral buds by the terminal bud of a shoot

apical meristem -n

  1. a meristem at the apex of a root or shoot that is responsible for increase in length

apic·u·late [ə-'pi-kyə-lət, ā-] -adj

  1. ending abruptly in a small distinct point
    • an apiculate leaf

api·cul·ture ['ā-pə-,kəl-chər] -n, adj

  1. the keeping of bees esp. on a large scale

apiece [ə-'pēs] -adv

  1. for each one : individually

Apis ['ā-pəs] -n

  1. a sacred bull worshipped by the ancient Egyptians

ap·ish ['ā-pish] -adj, adv, n

  1. : resembling an ape: as
  2. extremely silly or affected
    • apish antics
  3. given to slavish imitation

APL [,ā-(,)pē-'el] -n

  1. a computer programming language designed esp. for the concise representation of algorithms

ap·la·nat·ic [,a-plə-'na-tik] -adj

  1. free from or corrected for spherical aberration
    • an aplanatic lens

aplas·tic anemia [(,)ā-'plas-tik-] -n

  1. anemia that is characterized by defective function of the blood-forming organs (as the bone marrow) and is caused by toxic agents (as chemicals or X-rays) or is idiopathic in origin

aplen·ty [ə-'plen-tē] -adj

  1. being in plenty or abundance used postpositively
    • money aplenty for all their needs

aplenty -adv

  1. in abundance : plentifully
  2. very much : extremely
    • scared aplenty

ap·lite ['a-,plīt] -n, adj

  1. a fine-grained light-colored granite consisting almost entirely of quartz and feldspar

aplomb [ə-'pläm, -'pləm] -n

  1. complete and confident composure or self-assurance : poise

ap·nea ['ap-nē-ə] -n, adj

  1. transient cessation of respiration
  2. sleep apnea
  3. asphyxia

ap·noea ['ap-nē-ə] -n, adj

(variant of apnea)

  1. transient cessation of respiration
  2. sleep apnea
  3. asphyxia

apo ['a-pō] -n, pl

  1. apolipoprotein usu. used with a letter or letter and number

APO -abbr

  1. army post office

apo- -prefix

  1. away from : off
    • ap helion
  2. detached : separate
    • apo gamy
  3. formed from : related to
    • apo morphine

Apoc -abbr

  1. Apocalypse
  2. Apocrypha
  3. apocryphal

apoc·a·lypse [ə-'pä-kə-,lips] -n

  1. one of the Jewish and Christian writings of 200 b.c.to a.d.150 marked by pseudonymity, symbolic imagery, and the expectation of an imminent cosmic cataclysm in which God destroys the ruling powers of evil and raises the righteous to life in a messianic kingdom
  2. revelation
  3. something viewed as a prophetic revelation
  4. armageddon
  5. a great disaster
    • an environmental apocalypse

apoc·a·lyp·tic [ə-,pä-kə-'lip-tik] -adj, adv

  1. of, relating to, or resembling an apocalypse
  2. forecasting the ultimate destiny of the world : prophetic
  3. foreboding imminent disaster or final doom : terrible
  4. wildly unrestrained : grandiose
  5. ultimately decisive : climactic
    • an apocalyptic battle

apoc·a·lyp·ti·cism [-tə-,si-zəm] -n

  1. apocalyptic expectation
  2. a doctrine concerning an imminent end of the world and an ensuing general resurrection and final judgment

apoc·a·lyp·tist [ə-'pä-kə-,lip-tist] -n

  1. the writer of an apocalypse

apo·chro·mat·ic [,a-pə-krō-'ma-tik] -adj

  1. free from chromatic and spherical aberration
    • an apochromatic lens

apoc·o·pe [ə-'pä-kə-(,)pē] -n

  1. the loss of one or more sounds or letters at the end of a word (as in singfrom Old English singan)

apo·crine ['a-pə-krən, -,krīn, -,krēn] -adj

  1. producing a fluid secretion by pinching off one end of the secretory cell while leaving the rest intact
    • an apocrine gland
  2. produced by an apocrine gland

apoc·ry·pha [ə-'pä-krə-fə] -n pl but sing or pl in constr

  1. writings or statements of dubious authenticity
  2. books included in the Septuagint and Vulgate but excluded from the Jewish and Protestant canons of the Old Testament
  3. early Christian writings not included in the New Testament

apoc·ry·phal [-fəl] -adj, adv, n

  1. of doubtful authenticity : spurious
  2. of or resembling the Apocrypha

apo·dic·tic [,a-pə-'dik-tik] -adj, adv

  1. expressing or of the nature of necessary truth or absolute certainty

apod·o·sis [ə-'pä-də-səs] -n

  1. the main clause of a conditional sentence

apo·en·zyme [,a-pō-'en-,zīm] -n

  1. a protein that forms an active enzyme system by combination with a coenzyme and determines the specificity of this system for a substrate

apog·a·my [ə-'pä-gə-mē] -n

  1. development of a sporophyte from a gametophyte without fertilization

apo·gee ['a-pə-(,)jē] -n, adj

  1. the point in the orbit of an object (as a satellite) orbiting the earth that is at the greatest distance from the center of the earth
  2. the point farthest from a planet or a satellite (as the moon) reached by an object orbiting it
  3. the farthest or highest point : culmination
    • Aegean civilization reached its apogee in Crete

apo·li·po·pro·tein [,a-pō-,lī-pō-'prō-,tēn, -,li-, -,tē-ən] -n

  1. a protein that combines with a lipid to form a lipoprotein often used with a letter or letter and number

apo·lit·i·cal [,ā-pə-'li-ti-kəl] -adj, adv, n

  1. having no interest or involvement in political affairs
  2. having an aversion to politics or political affairs
  3. having no political significance

Ap·ol·lin·i·an [,a-pə-'li-nē-ən] -adj

  1. apollonian

Apol·lo [ə-'pä-(,)lō] -n

  1. the Greek and Roman god of sunlight, prophecy, music, and poetry
  2. any of a class of asteroids having an orbit that extends from inside to beyond the earth's orbit

Ap·ol·lo·ni·an [,a-pə-'lō-nē-ən] -adj

  1. of, relating to, or resembling the god Apollo
  2. harmonious, measured, ordered, or balanced in character

Apol·lyon [ə-'päl-yən, -'pä-lē-ən] -n

  1. the angel of the bottomless pit in the Book of Revelation

apol·o·get·ic [ə-,pä-lə-'je-tik] -n

  1. apologetics

apologetic [-ti-k(ə-)lē] -adj, adv

  1. offered in defense or vindication
    • the apologetic writings of the early Christians
  2. offered by way of excuse or apology
    • an apologetic smile
  3. regretfully acknowledging fault or failure : contrite
    • replied in an apologetic tone

apol·o·get·ics [-tiks] -n pl but sing or pl in constr

  1. systematic argumentative discourse in defense (as of a doctrine)
  2. a branch of theology devoted to the defense of the divine origin and authority of Christianity

ap·o·lo·gia [,a-pə-'lō-j(ē-)ə] -n

  1. a defense esp. of one's opinions, position, or actions
    • the finest apologia or explanation of what drives a man to devote his life to pure mathematics -- Brit. Book News

apol·o·gise [-,jīz] -vi, n

(variant of apologize)

  1. to make an apology

apol·o·gist [ə-'pä-lə-jist] -n

  1. one who speaks or writes in defense of someone or something

apol·o·gize [-,jīz] -vi, n

  1. to make an apology

ap·o·logue ['a-pə-,lȯg, -,läg] -n

  1. an allegorical narrative usu. intended to convey a moral

apol·o·gy [ə-'pä-lə-jē] -n

  1. a formal justification : defense
  2. excuse
  3. an admission of error or discourtesy accompanied by an expression of regret
    • a public apology
  4. a poor substitute : makeshift

apo·lune ['a-pə-,lün] -n

  1. the point in the path of a body orbiting the moon that is farthest from the center of the moon

apo·mict ['a-pə-,mikt] -n, adj, adv

  1. one produced or reproducing by apomixis

apo·mix·is [,a-pə-'mik-səs] -n

  1. reproduction (as apogamy or parthenogenesis) involving specialized generative tissues but not dependent on fertilization

apo·mor·phine [,a-pə-'mȯr-,fēn] -n

  1. a crystalline morphine derivative C 17H 17NO 2that is a dopamine agonist and is administered in the form of its hydrochloride for its powerful emetic action

apo·neu·ro·sis [,a-pə-nu̇-'rō-səs, -nyu̇-] -n, adj

  1. a broad flat sheet of dense fibrous collagenous connective tissue that covers, invests, and forms the terminations and attachments of various muscles

apoph·a·sis [ə-'pä-fə-səs] -n

  1. the raising of an issue by claiming not to mention it (as in we won't discuss his past crimes)

ap·o·phthegm ['a-pə-,them] -n, adj

(variant of apothegm)

  1. a short, pithy, and instructive saying or formulation : aphorism

apo·phyl·lite [,a-pə-'fi-,līt, ə-'pä-fə-,līt] -n

  1. a mineral composed of a hydrous silicate of potassium, calcium, and fluorine that is related to the zeolites and is usu. found in transparent square prisms or white or grayish masses

apoph·y·sis [ə-'pä-fə-səs] -n, adj

  1. an expanded or projecting part esp. of an organism

ap·o·plec·tic [,a-pə-'plek-tik] -adj, adv

  1. of, relating to, or causing stroke
  2. affected with, inclined to, or showing symptoms of stroke
  3. of a kind to cause or apparently cause stroke
    • an apoplectic rage
  4. greatly excited or angered
    • was apoplectic over the news

ap·o·plexy ['a-pə-,plek-sē] -n

  1. stroke

ap·o·pto·sis [,a-pəp-'tō-səs, -pə-'tō-] -n, adj

  1. a genetically directed process of cell self-destruction that is marked by the fragmentation of nuclear DNA, is activated either by the presence of a stimulus or removal of a suppressing agent or stimulus, and is a normal physiological process eliminating DNA-damaged, superfluous, or unwanted cells called also programmed cell death

apo·ria [ə-'pȯr-ē-ə] -n

  1. an expression of real or pretended doubt or uncertainty esp. for rhetorical effect
  2. a logical impasse or contradiction
  3. a radical contradiction in the import of a text or theory that is seen in deconstruction as inevitable

aport [ə-'pȯrt] -adv

  1. on or toward the left side of a ship
    • put the helm hard aport

apos ['a-pō] -n, pl

(variant of apo)

  1. apolipoprotein usu. used with a letter or letter and number

apo·se·mat·ic [,a-pə-si-'ma-tik] -adj, adv

  1. being conspicuous and serving to warn
    • aposematic coloration in butterflies

ap·o·si·o·pe·sis [,a-pə-,sī-ə-'pē-səs] -n, adj

  1. the leaving of a thought incomplete usu. by a sudden breaking off (as in his behavior was-but I blush to mention that)

apos·po·ry ['a-pə-,spȯr-ē, ə-'päs-pə-rē] -n

  1. production of gametophytes directly from diploid cells of the sporophytes without spore formation (as in certain ferns and mosses)

apos·ta·sy [ə-'päs-tə-sē] -n

  1. renunciation of a religious faith
  2. abandonment of a previous loyalty : defection

apos·tate [ə-'päs-,tāt, -tət] -n, adj

  1. one who commits apostasy

apos·ta·tise [ə-'päs-tə-,tīz] -vi

(variant of apostatize)

  1. to commit apostasy

apos·ta·tize [ə-'päs-tə-,tīz] -vi

  1. to commit apostasy

apos·tle [ə-'pä-səl] -n

  1. : one sent on a mission: as
  2. one of an authoritative New Testament group sent out to preach the gospel and made up esp. of Christ's 12 original disciples and Paul
  3. the first prominent Christian missionary to a region or group
  4. a person who initiates a great moral reform or who first advocates an important belief or system
  5. an ardent supporter : adherent
  6. the highest ecclesiastical official in some church organizations
  7. one of a Mormon administrative council of 12 men

Apostles' Creed -n

  1. a Christian statement of belief ascribed to the Twelve Apostles and used esp. in public worship

apos·to·late [ə-'päs-tə-,lāt, -lət] -n

  1. the office or mission of an apostle
  2. an association of persons dedicated to the propagation of a religion or a doctrine

ap·os·tol·ic [,a-pə-'stä-lik] -adj, n

  1. of or relating to an apostle
  2. of, relating to, or conforming to the teachings of the New Testament apostles
  3. of or relating to a succession of spiritual authority from the apostles held (as by Roman Catholics, Anglicans, and Eastern Orthodox) to be perpetuated by successive ordinations of bishops and to be necessary for valid sacraments and orders
  4. papal

apostolic delegate -n

  1. an ecclesiastical representative of the Holy See to the Catholic hierarchy of another country

Apostolic Father -n

  1. a church father of the first or second century a.d.

apos·tro·phe [ə-'päs-trə-(,)fē] -n, adj

  1. the addressing of a usu. absent person or a usu. personified thing rhetorically
    • Carlyle's O Liberty, what things are done in thy name is an example of apostrophe

apostrophe -n, adj

  1. a mark ' used to indicate the omission of letters or figures, the possessive case, or the plural of letters or figures

apos·tro·phise [ə-'päs-trə-,fīz] -vb

(variant of apostrophize)

  1. to address by or in apostrophe
  2. to make use of apostrophe

apos·tro·phize [ə-'päs-trə-,fīz] -vb

  1. to address by or in apostrophe
  2. to make use of apostrophe

apothecaries' measure -n

  1. a system of liquid units of measure used chiefly by pharmacists called also apothecary measure

apothecaries' weight -n

  1. a system of weights used chiefly by pharmacists called also apothecary weight

apoth·e·cary [ə-'pä-thə-,ker-ē, -,ke-rē] -n

  1. one who prepares and sells drugs or compounds for medicinal purposes
  2. pharmacy

apo·the·ci·um [,a-pə-'thē-shē-əm, -sē-] -n, adj

  1. a spore-bearing structure in many lichens and fungi consisting of a discoid or cupped body bearing asci on the exposed flat or concave surface

ap·o·thegm ['a-pə-,them] -n, adj

  1. a short, pithy, and instructive saying or formulation : aphorism

ap·o·them ['a-pə-,them] -n

  1. the perpendicular from the center of a regular polygon to one of the sides

apo·the·o·sis [ə-,pä-thē-'ō-səs, ,a-pə-'thē-ə-səs] -n, vt

  1. elevation to divine status : deification
  2. the perfect example : quintessence
    • this is the literary apotheosis of the shaggy dog story -- Thomas Sutcliffe

apo·tro·pa·ic [,a-pə-trō-'pā-ik] -adj, adv

  1. designed to avert evil
    • an apotropaic ritual

app ['ap] -n

  1. application
  2. apparatus
  3. appendix
  4. appliance

Ap·pa·la·chian [,a-pə-'lā-ch(ē-)ən, -'la-, -sh(ē-)ən] -n

  1. a native or resident of the Appalachian mountain area

Appalachian dulcimer -n

  1. dulcimer

ap·pall [ə-'pȯl] -vb

  1. weaken, fail
  2. to overcome with consternation, shock, or dismay
    • we were appall ed by his behavior

ap·pall·ing -adj, adv

  1. inspiring horror, dismay, or disgust
    • living under appalling conditions

Ap·pa·loo·sa [,a-pə-'lü-sə] -n

  1. any of a breed of rugged saddle horses developed in western No. America and usu. having a white or solid-colored coat with small spots

ap·pa·nage ['a-pə-nij] -n

  1. a grant (as of land or revenue) made by a sovereign or a legislative body to a dependent member of the royal family or a principal vassal
  2. a property or privilege appropriated to or by a person as something due
  3. a rightful endowment or adjunct

ap·pa·rat ['a-pə-,rat, ,ä-pə-'rät] -n

  1. apparatus

ap·pa·rat·chik [,ä-pə-'rä(t)-chik] -n

  1. a member of a Communist apparat
  2. a blindly devoted official, follower, or member of an organization (as a corporation or political party)
    • a movie studio apparatchik

ap·pa·ra·tus [,a-pə-'ra-təs, -'rā-] -n

  1. a set of materials or equipment designed for a particular use
  2. a group of anatomical or cytological parts functioning together
    • mitotic apparatus
  3. an instrument or appliance designed for a specific operation
  4. : the functional processes by means of which a systematized activity is carried out
    • the apparatus of society
    : as
  5. the machinery of government
  6. the organization of a political party or an underground movement

ap·par·el [ə-'per-əl, -'pa-rəl] -vt

  1. to put clothes on : dress
  2. adorn, embellish
    • accused of apparel ing the truth

apparel -n

  1. the equipment (as sails and rigging) of a ship
  2. personal attire : clothing
  3. something that clothes or adorns
    • the bright apparel of spring

ap·par·ent [ə-'per-ənt, -'pa-rənt] -adj, n

  1. open to view : visible
  2. clear or manifest to the understanding
    • reasons that are readily apparent
  3. appearing as actual to the eye or mind
  4. having an indefeasible right to succeed to a title or estate
  5. manifest to the senses or mind as real or true on the basis of evidence that may or may not be factually valid
    • the air of spontaneity is perhaps more apparent than real -- J. R. Sutherland

ap·par·ent·ly [-lē] -adv

  1. it seems apparent
    • the window had apparently been forced open
    • apparently, we're supposed to wait here

apparent magnitude -n

  1. the luminosity of a celestial body (as a star) as observed from the earth

apparent time -n

  1. the time of day indicated by the hour angle of the sun or by a sundial

ap·pa·ri·tion [,a-pə-'ri-shən] -n, adj

  1. an unusual or unexpected sight : phenomenon
  2. a ghostly figure
  3. the act of becoming visible : appearance

ap·par·i·tor [ə-'per-ə-tər, -'pa-rə] -n

  1. an official formerly sent to carry out the orders of a magistrate, judge, or court

ap·peal [ə-'pēl] -n

  1. a legal proceeding by which a case is brought before a higher court for review of the decision of a lower court
  2. a criminal accusation
  3. an application (as to a recognized authority) for corroboration, vindication, or decision
  4. an earnest plea : entreaty
    • an appeal for help
  5. an organized request for donations
    • the annual appeal
  6. the power of arousing a sympathetic response : attraction
    • movies had a great appeal for him

appeal [-,pē-lə-'bi-lə-tē] -vb, n, adj

  1. to charge with a crime : accuse
  2. to take proceedings to have (a lower court's decision) reviewed in a higher court
  3. to take a lower court's decision to a higher court for review
  4. to call upon another for corroboration, vindication, or decision
  5. to make an earnest request
    • appeal ed to them for help
  6. to arouse a sympathetic response
    • that idea appeal s to him

ap·peal·ing [ə-'pē-liŋ] -adj, adv

  1. marked by earnest entreaty : imploring
  2. having appeal : pleasing
    • an appealing design

ap·pear [ə-'pir] -vi

  1. to be or come in sight
    • the sun appear s on the horizon
  2. to show up
    • appear s promptly at eight each day
  3. to come formally before an authoritative body
    • must appear in court today
  4. to have an outward aspect : seem
    • appear s happy enough
  5. to become evident or manifest
    • there appear s to be evidence to the contrary
  6. to come into public view
    • first appear ed on a television variety show
    • the book appear ed in print a few years ago
  7. to come into existence
    • hominids appear ed late in the evolutionary chain

ap·pear·ance [ə-'pir-ən(t)s] -n

  1. external show : semblance
    • although hostile, he preserved an appearance of neutrality
  2. outward aspect : look
    • had a fierce appearance
  3. outward indication
    • trying to keep up appearance s
  4. a sense impression or aspect of a thing
    • the blue of distant hills is only an appearance
  5. the world of sensible phenomena
  6. the act, action, or process of appearing
  7. the presentation of oneself in court as a party to an action often through the representation of an attorney
  8. something that appears : phenomenon
  9. an instance of appearing : occurrence

ap·pease [ə-'pēz] -vt, adj, n

  1. to bring to a state of peace or quiet : calm
  2. to cause to subside : allay
    • appeased my hunger
  3. pacify, conciliate
  4. to buy off (an aggressor) by concessions usu. at the sacrifice of principles

ap·pel·lant [ə-'pe-lənt] -adj

  1. of or relating to an appeal : appellate
    • an appellant court

appellant -n

  1. one that appeals
  2. one that appeals from a judicial decision or decree

ap·pel·late [ə-'pe-lət] -adj

  1. of, relating to, or recognizing appeals
  2. having the power to review the judgment of another tribunal
    • an appellate court

ap·pel·la·tion [,a-pə-'lā-shən] -n

  1. an identifying name or title : designation
  2. the act of calling by a name
  3. a geographical name (as of a region, village, or vineyard) under which a winegrower is authorized to identify and market wine
  4. the area designated by such a name

ap·pel·la·tive [ə-'pe-lə-tiv] -adj, n, adv

  1. of or relating to a common noun
  2. of, relating to, or inclined to the giving of names

ap·pel·lee [,a-pə-'lē] -n

  1. one against whom an appeal is taken

ap·pend [ə-'pend] -vt

  1. attach, affix
  2. to add as a supplement or appendix (as in a book)

ap·pend·age [ə-'pen-dij] -n

  1. an adjunct to something larger or more important : appurtenance
  2. a usu. projecting part of an animal or plant body that is typically smaller and of less functional importance than the main part to which it is attached
  3. a limb or analogous part (as a seta)
  4. a dependent or subordinate person

ap·pen·dant [ə-'pen-dənt] -adj, n

  1. belonging as a right by prescription used of annexed land in English law
  2. associated as an attendant circumstance
  3. attached as an appendage
    • a seal appendant to a document

ap·pen·dec·to·my [,a-pən-'dek-tə-mē, ,a-,pen-] -n

  1. surgical removal of the vermiform appendix

ap·pen·di·cec·to·my [ə-,pen-də-'sek-tə-mē] -n

  1. appendectomy

ap·pen·di·ci·tis [ə-,pen-də-'sī-təs] -n

  1. inflammation of the vermiform appendix

ap·pen·dic·u·lar [,a-pən-'di-kyə-lər] -adj

  1. of or relating to an appendage and esp. a limb
    • the appendicular skeleton

ap·pen·dix [ə-'pen-diks] -n

  1. appendage
  2. supplementary material usu. attached at the end of a piece of writing
  3. a bodily outgrowth or process
  4. vermiform appendix

ap·per·ceive [,a-pər-'sēv] -vt

  1. to have apperception of

ap·per·cep·tion [-'sep-shən] -n, adj

  1. introspective self-consciousness
  2. mental perception
  3. the process of understanding something perceived in terms of previous experience

ap·per·tain [,a-pər-'tān] -vi

  1. to belong or be connected as a rightful part or attribute : pertain

ap·pe·tence ['a-pə-tən(t)s] -n

  1. appetency

ap·pe·ten·cy [-tən(t)-sē] -n, adj

  1. a fixed and strong desire : appetite

ap·pe·tis·er ['a-pə-,tī-zər] -n

(variant of appetizer)

  1. a food or drink that stimulates the appetite and is usu. served before a meal
  2. something that stimulates a desire for more
    • a literary appetizer

ap·pe·tite ['a-pə-,tīt] -n, adj

  1. any of the instinctive desires necessary to keep up organic life
  2. the desire to eat
  3. an inherent craving
    • an insatiable appetite for work
  4. taste, preference
    • the cultural appetite s of the time -- J. D. Hart

ap·pe·tiz·er ['a-pə-,tī-zər] -n

  1. a food or drink that stimulates the appetite and is usu. served before a meal
  2. something that stimulates a desire for more
    • a literary appetizer

ap·pe·tiz·ing [-,tī-ziŋ] -adj, adv

  1. appealing to the appetite esp. in appearance or aroma
  2. appealing to one's taste
    • an appetizing display of merchandise

appl -abbr

  1. applied

ap·plaud [ə-'plȯd] -vb, adj, adv, n

  1. to express approval esp. by clapping the hands
  2. to express approval of : praise
    • applaud her efforts to lose weight
  3. to show approval of esp. by clapping the hands

ap·plause [ə-'plȯz] -n

  1. marked commendation : acclaim
    • the kind of applause every really creative writer wants -- Robert Tallant
  2. approval publicly expressed (as by clapping the hands)

ap·ple ['a-pəl] -n

  1. the fleshy usu. rounded red, yellow, or green edible pome fruit of a usu. cultivated tree (genus Malus) of the rose family
  2. an apple tree
  3. a fruit (as a star apple) or other vegetative growth (as an oak apple) suggestive of an apple

apple butter -n

  1. a thick brown spread made by cooking apples with sugar and spices usu. in cider

ap·ple·cart [-,kärt] -n

  1. a plan, system, situation, or undertaking that may be disrupted or terminated
    • upset the applecart

ap·plecheeked ['a-pəl-,chēkt] -adj

  1. having cheeks the color of red apples
    • applecheeked youngsters

ap·ple·jack [-,jak] -n

  1. brandy distilled from hard cider
  2. an alcoholic beverage traditionally made by freezing hard cider and siphoning off the concentrated liquor

ap·pleknock·er [-,nä-kər] -n

  1. rustic

apple maggot -n

  1. a dipteran fly ( Rhagoletis pomonella) whose larva burrows in and feeds esp. on apples

ap·plepie ['a-pəl-'pī] -adj

  1. excellent, perfect
    • applepie order
  2. of, relating to, or characterized by traditionally American values (as honesty or simplicity)
    • is the epitome of applepie wholesomeness

ap·plepol·ish ['a-pəl-,pä-lish] -vb, n

  1. to attempt to ingratiate oneself : toady
  2. to curry favor with (as by flattery)

ap·ple·sauce [-,sȯs] -n

  1. a relish or dessert made of apples stewed to a pulp and sweetened
  2. bunkum, nonsense

apple scab -n

  1. a disease of apple trees caused by a fungus ( Venturia inaequalis) producing dark blotches or lesions on the leaves, fruit, and sometimes the young twigs

ap·plet ['a-plət, -(,)plet] -n

  1. a short computer application esp. for performing a simple specific task

ap·pli·ance [ə-'plī-ən(t)s] -n

  1. an act of applying
  2. a piece of equipment for adapting a tool or machine to a special purpose : attachment
  3. an instrument or device designed for a particular use or function
    • an orthodontic appliance
  4. a household or office device (as a stove, fan, or refrigerator) operated by gas or electric current
  5. fire engine
  6. compliance

ap·pli·ca·ble ['a-pli-kə-bəl also ə-'pli-kə-] -adj, n

  1. capable of or suitable for being applied : appropriate
    • statutes applicable to the case

ap·pli·cant ['a-pli-kənt] -n

  1. one who applies
    • a job applicant

ap·pli·ca·tion [,a-plə-'kā-shən] -n

  1. : an act of applying:
  2. an act of putting to use
    • application of new techniques
  3. a use to which something is put
    • new application s for old remedies
  4. a program (as a word processor or a spreadsheet) that performs one of the major tasks for which a computer is used
  5. an act of administering or superposing
    • application of paint to a house
  6. assiduous attention
    • succeeds by application to her studies
  7. request, petition
    • an application for financial aid
  8. a form used in making a request
  9. the practical inference to be derived from a discourse (as a moral tale)
  10. a medicated or protective layer or material
    • an oily application for dry skin
  11. capacity for practical use
    • words of varied application

ap·pli·ca·tive ['a-plə-,kā-tiv, ə-'pli-kə-] -adj, adv

  1. applicable, practical
  2. put to use : applied

ap·pli·ca·tor ['a-plə-,kā-tər] -n

  1. one that applies
  2. a device for applying a substance (as medicine or polish)

ap·pli·ca·to·ry ['a-pli-kə-,tȯr-ē, ə-'pli-kə-] -adj

  1. capable of being applied

ap·plied [ə-'plīd] -adj

  1. put to practical use
    • applied art
  2. applying general principles to solve definite problems
    • applied sciences
  3. working in an applied science
    • an applied physicist

ap·pli·que [,a-plə-'kā] -n

  1. a cutout decoration fastened to a larger piece of material

applique -vt

  1. to apply (as a decoration or ornament) to a larger surface : overlay

ap·ply [ə-'plī] -vb, n

  1. to put to use esp. for some practical purpose
    • applies pressure to get what he wants
  2. to bring into action
    • apply the brakes
  3. to lay or spread on
    • apply varnish
  4. to put into operation or effect
    • apply a law
  5. to employ diligently or with close attention
    • should apply yourself to your work
  6. to have relevance or a valid connection
    • this rule applies to freshmen only
  7. to make an appeal or request esp. in the form of a written application
    • apply for a job

ap·pog·gia·tu·ra [ə-,pä-jə-'tu̇r-ə] -n

  1. an embellishing note or tone preceding an essential melodic note or tone and usu. written as a note of smaller size

ap·point [ə-'pȯint] -vb

  1. to fix or set officially
    • appoint a trial date
  2. to name officially
    • will appoint her director of the program
  3. arrange
  4. to determine the disposition of (an estate) to someone by virtue of a power of appointment
  5. to provide with complete and usu. appropriate or elegant furnishings or equipment
    • a beautifully appoint ed room
  6. to exercise a power of appointment

ap·poin·tee [ə-,pȯin-'tē, ,a-] -n

  1. one who is appointed
  2. one to whom an estate is appointed

ap·point·ive [ə-'pȯin-tiv] -adj

  1. of, relating to, or filled by appointment
    • an appointive office

ap·point·ment [ə-'pȯint-mənt] -n

  1. an act of appointing : designation
  2. the designation by virtue of a vested power of a person to enjoy an estate
  3. an arrangement for a meeting : engagement
    • an appointment for an interview
  4. equipment, furnishings usu. used in pl.
    • expensive homes with luxurious appointment s
  5. a nonelective office or position
    • holds an academic appointment

ap·por·tion [ə-'pȯr-shən] -vt, adj

  1. to divide and share out according to a plan
  2. to make a proportionate division or distribution of

ap·por·tion·ment [-shən-mənt] -n

  1. an act or result of apportioning
  2. the apportioning of representatives or taxes among the states according to U.S. law

ap·pose [a-'pōz] -vt

  1. to put before : apply (one thing) to another
  2. to place in juxtaposition or proximity

ap·po·site ['a-pə-zət] -adj, adv, n

  1. highly pertinent or appropriate : apt
    • apposite remarks

ap·po·si·tion [,a-pə-'zi-shən] -n, adj

  1. a grammatical construction in which two usu. adjacent nouns having the same referent stand in the same syntactical relation to the rest of a sentence (as the poetand Burnsin a biography of the poet Burns)
  2. the relation of one of such a pair of nouns or noun equivalents to the other
  3. an act or instance of apposing
  4. the deposition of successive layers upon those already present (as in cell walls)
  5. the state of being apposed

ap·pos·i·tive [ə-'pä-zə-tiv, a-] -adj, n, adv

  1. of, relating to, or standing in grammatical apposition

ap·prais·al [ə-'prā-zəl] -n

  1. an act or instance of appraising
  2. a valuation of property by the estimate of an authorized person

ap·praise [ə-'prāz] -vt, n, adv, adj

  1. to set a value on : estimate the amount of
    • appraise the damage
  2. to evaluate the worth, significance, or status of
  3. to give an expert judgment of the value or merit of
    • appraise an actor's career

ap·pre·cia·ble [ə-'prē-shə-bəl, -'pri-sh(ē-)ə-bəl] -adj, adv

  1. capable of being perceived or measured
    • no appreciable difference

ap·pre·ci·ate [ə-'prē-shē-,āt, -'pri- also -'prē-sē-] -vb, n, adj

  1. to grasp the nature, worth, quality, or significance of
    • appreciate the difference between right and wrong
  2. to value or admire highly
    • appreciate s our work
  3. to judge with heightened perception or understanding : be fully aware of
    • must see it to appreciate it
  4. to recognize with gratitude
    • certainly appreciate s your kindness
  5. to increase the value of
  6. to increase in number or value

ap·pre·ci·a·tion [ə-,prē-shē-'ā-shən, -,pri- also -,prē-sē-] -n

  1. judgment, evaluation
  2. a favorable critical estimate
  3. sensitive awareness
  4. recognition of aesthetic values
  5. an expression of admiration, approval, or gratitude
  6. increase in value

ap·pre·cia·tive [ə-'prē-shə-tiv, -'pri- also -'prē-shē-,ā-] -adj, adv, n

  1. having or showing appreciation
    • an appreciative audience
    • was appreciative of his good luck

ap·pre·hend [,a-pri-'hend] -vb

  1. arrest, seize
    • apprehend a thief
  2. to become aware of : perceive
  3. to anticipate esp. with anxiety, dread, or fear
  4. to grasp with the understanding : recognize the meaning of
  5. understand, grasp

ap·pre·hen·si·ble [,a-pri-'hen(t)-sə-bəl] -adj, adv

  1. capable of being apprehended
    • an easily apprehensible truth

ap·pre·hen·sion [,a-pri-'hen(t)-shən] -n

  1. the act or power of perceiving or comprehending
    • a person of dull apprehension
  2. the result of apprehending mentally : conception
    • according to popular apprehension
  3. seizure by legal process : arrest
    • apprehension of a criminal
  4. suspicion or fear esp. of future evil : foreboding
    • an atmosphere of nervous apprehension

ap·pre·hen·sive [-'hen(t)-siv] -adj, adv, n

  1. capable of apprehending or quick to do so : discerning
  2. having apprehension : cognizant
  3. viewing the future with anxiety or alarm

ap·pren·tice [ə-'pren-təs] -n

  1. one bound by indenture to serve another for a prescribed period with a view to learning an art or trade
  2. one who is learning by practical experience under skilled workers a trade, art, or calling
  3. an inexperienced person : novice
    • an apprentice in cooking

apprentice -vb

  1. to set at work as an apprentice
  2. to bind to an apprenticeship by contract or indenture
  3. to serve as an apprentice

ap·pressed [a-'prest] -adj

  1. pressed close to or lying flat against something
    • leaves appressed against the stem

ap·pres·so·ri·um [,a-pre-'sȯr-ē-əm] -n

  1. the flattened thickened tip of a hyphal branch by which some parasitic fungi attach to and penetrate their host

ap·prise [ə-'prīz] -vt

  1. to give notice to : tell
    • they apprised him of his rights

ap·prize [ə-'prīz] -vt

  1. value, appreciate

appro -abbr

  1. approval

ap·proach [ə-'prōch] -vb

  1. to draw closer to : near
    • approach a destination
  2. to come very near to : be almost the same as
    • its mathematics approach es mysticism -- Theodore Sturgeon
    • as the quantity x approach es zero
  3. to make advances to esp. in order to create a desired result
    • was approach ed by several Broadway producers
  4. to take preliminary steps toward accomplishment or full knowledge or experience of
    • approach the subject with an open mind
  5. to draw nearer
    • the time is fast approach ing
  6. to make an approach in golf

approach -n

  1. an act or instance of approaching
    • the approach of summer
  2. approximation
    • in this book he makes his closest approach to greatness
  3. the taking of preliminary steps toward a particular purpose
    • experimenting with new lines of approach
  4. a particular manner of taking such steps
    • a highly individual approach to language
  5. a means of access : avenue
  6. a golf shot from the fairway toward the green
  7. the steps taken by a bowler before delivering the ball
  8. the part of the alley behind the foul line from which the bowler delivers the ball
  9. the descent of an aircraft toward a landing place

ap·proach·able [ə-'prō-chə-bəl] -adj, n

  1. capable of being approached : accessible
  2. easy to meet or deal with
    • friendly and approachable people

ap·pro·bate ['a-prə-,bāt] -vt

  1. approve, sanction

ap·pro·ba·tion [,a-prə-'bā-shən] -n, adj

  1. proof
  2. an act of approving formally or officially
  3. commendation, praise

ap·pro·pri·ate [ə-'prō-prē-,āt] -vt, adj, n

  1. to take exclusive possession of : annex
    • no one should appropriate a common benefit
  2. to set apart for or assign to a particular purpose or use
    • appropriate money for the research program
  3. to take or make use of without authority or right
  4. especially suitable or compatible : fitting
    • an appropriate response
    • remarks appropriate to the occasion

ap·pro·pri·a·tion [ə-,prō-prē-'ā-shən] -n, adj

  1. an act or instance of appropriating
  2. something that has been appropriated
  3. money set aside by formal action for a specific use

ap·prov·able [ə-'prü-və-bəl] -adj, adv

  1. capable or worthy of being approved
    • an approvable plan

ap·prov·al [ə-'prü-vəl] -n

  1. an act or instance of approving : approbation

ap·prove [ə-'prüv] -vb, adv

  1. prove, attest
  2. to have or express a favorable opinion of
    • couldn't approve such conduct
  3. to accept as satisfactory
    • hopes she will approve the date of the meeting
  4. to give formal or official sanction to : ratify
    • Congress approved the proposed budget
  5. to take a favorable view
    • doesn't approve of fighting

approved school -n

  1. a school for juvenile delinquents

approx -abbr

  1. approximate; approximately

ap·prox·i·mate [ə-'präk-sə-mət] -adj, adv

  1. located close together
    • approximate leaves
  2. nearly correct or exact
    • an approximate solution
  3. to bring near or close
  4. to bring (cut edges of tissue) together
  5. to come near to or be close to in position, value, or characteristics
    • a child tries to approximate his parents' speech
  6. to come close usu. used with to

ap·prox·i·ma·tion [ə-,präk-sə-'mā-shən] -n, adj

  1. the act or process of drawing together
  2. the quality or state of being close or near
    • an approximation to the truth
    • an approximation of justice
  3. something that is approximate
  4. a mathematical quantity that is close in value to but not the same as a desired quantity

appt -abbr

  1. appoint; appointed; appointment

apptd -abbr

  1. appointed

ap·pur·te·nance [ə-'pərt-nən(t)s, -'pər-tə-nən(t)s] -n

  1. an incidental right (as a right-of-way) attached to a principal property right and passing in possession with it
  2. a subordinate part or adjunct
    • the appurtenance of welcome is fashion and ceremony -- Shak.
  3. accessory objects : apparatus
    • the appurtenance s of wealth

ap·pur·te·nant [ə-'pərt-nənt, -'pər-tə-nənt] -adj, n

  1. constituting a legal accompaniment
  2. auxiliary, accessory
    • appurtenant equipment

Apr -abbr

  1. April

APR -abbr

  1. annual percentage rate

aprax·ia [(,)ā-'prak-sē-ə] -n, adj

  1. loss or impairment of the ability to execute complex coordinated movements without muscular or sensory impairment

apres [(,)ä-'prā, 'ä-,prā; 'a-,] -prep

  1. after
    • apres tennis
    usu. used in combination
    • apres -theater party

apresski [,ä-,prā-'skē, ,a-] -n

  1. social activity (as at a ski lodge) after a day's skiing

apri·cot ['a-prə-,kät, 'ā-] -n

  1. the oval orange-colored fruit of a temperate-zone tree ( Prunus armeniaca) resembling the related peach and plum in flavor
  2. a tree that bears apricots
  3. a variable color averaging a moderate orange

April ['ā-prəl] -n

  1. the fourth month of the Gregorian calendar

April fool -n

  1. the butt of a joke or trick played on April Fools' Day
  2. such a joke or trick

April Fools' Day -n

  1. April 1 characteristically marked by the playing of practical jokes

apron ['ā-prən, -pərn] -n, adj

  1. a garment usu. of cloth, plastic, or leather usu. tied around the waist and used to protect clothing or adorn a costume
  2. : something that suggests or resembles an apron in shape, position, or use: as
  3. the lower member under the sill of the interior casing of a window
  4. an upward or downward vertical extension of a bathroom fixture (as a sink or tub)
  5. an endless belt for carrying material
  6. an extensive fan-shaped deposit of detritus
  7. the part of the stage in front of the proscenium arch
  8. the area along the waterfront edge of a pier or wharf
  9. a shield (as of concrete or gravel) to protect against erosion (as of a waterway) by water
  10. the extensive paved part of an airport immediately adjacent to the terminal area or hangars

apron string -n

  1. the string of an apron usu. used in pl. as a symbol of dominance or complete control
    • though 40 years old he was still tied to his mother's apron strings

ap·ro·pos [,a-prə-'pō, 'a-prə-,] -adv

  1. at an opportune time : seasonably
  2. by way of interjection or further comment : with regard to the present topic

apropos -adj

  1. being both relevant and opportune
    • apropos comments
  2. apropos of

apropos of -prep

  1. with regard to : concerning

apro·tic [(,)ā-'prō-tik] -adj

  1. incapable of acting as a proton donor

apse ['aps] -n

  1. apsis
  2. a projecting part of a building (as a church) that is usu. semicircular in plan and vaulted

ap·si·dal ['ap-sə-dᵊl] -adj

  1. of or relating to an apse or apsis

ap·sis ['ap-səs] -n

  1. the point in an astronomical orbit at which the distance of the body from the center of attraction is either greatest or least
  2. apse

apt ['apt] -adj, adv, n

  1. unusually fitted or qualified : ready
    • proved an apt tool in the hands of the conspirators
  2. having a tendency : likely
    • plants apt to suffer from drought
  3. ordinarily disposed : inclined
    • apt to accept what is plausible as true
  4. suited to a purpose
  5. being to the point
    • an apt quotation
  6. keenly intelligent and responsive
    • an apt pupil
  7. apartment
  8. aptitude

ap·ter·ous ['ap-tə-rəs] -adj

  1. lacking wings
    • apterous insects

ap·ter·yx ['ap-tə-riks] -n

  1. kiwi

ap·ti·tude ['ap-tə-,tüd, -,tyüd] -n, adj, adv

  1. inclination, tendency
    • an aptitude for hard work
  2. a natural ability : talent
  3. capacity for learning
    • an aptitude for languages
  4. general suitability : aptness

aptitude test -n

  1. a standardized test designed to predict an individual's ability to learn certain skills

APU -abbr

  1. auxiliary power unit

ap·y·rase ['a-pə-,rās, -,rāz] -n

  1. any of several enzymes that catalyze the hydrolysis of ATP to AMP with the liberation of phosphate and energy