is ['bē] -vb

(variant of be)

  1. to equal in meaning : have the same connotation as : symbolize
    • God is love
    • January is the first month
    • let x be 10
  2. to have identity with
    • the first person I met was my brother
  3. to constitute the same class as
  4. to have a specified qualification or characterization
    • the leaves are green
  5. to belong to the class of
    • the fish is a trout
    used regularly in senses 1a through 1e as the copula of simple predication
  6. to have an objective existence : have reality or actuality : live
    • I think, therefore I am
  7. to have, maintain, or occupy a place, situation, or position
    • the book is on the table
  8. to remain unmolested, undisturbed, or uninterrupted used only in infinitive form
    • let him be
  9. to take place : occur
    • the concert was last night
  10. to come or go
    • has already been and gone
    • has never been to the circus
  11. belong, befall
  12. used with the past participle of transitive verbs as a passive-voice auxiliary
    • the money was found
    • the house is being built
  13. used as the auxiliary of the present participle in progressive tenses expressing continuous action
    • he is reading
    • I have been sleeping
  14. used with the past participle of some intransitive verbs as an auxiliary forming archaic perfect tenses
    • Christ is risen from the dead -- 1 Cor 15:20(DV)
  15. used with the infinitive with to to express futurity, arrangement in advance, or obligation
    • I am to interview him today
    • she was to become famous

IS -abbr

  1. information system

is- -comb form

  1. equal : homogeneous : uniform
    • is entropic
  2. isomeric
    • iso cyanate
  3. for or from different individuals of the same species
    • iso agglutinin

Isa -abbr

  1. Isaiah

ISA -abbr

  1. Industry Standard Architecture

Isaac ['ī-zik, -zək] -n

  1. the son of Abraham and father of Jacob according to the account in Genesis

Isa·iah [ī-'zā-ə, chiefly Brit -'zī-] -n

  1. a major Hebrew prophet in Judah about 740 to 701 b.c.
  2. a prophetic book of canonical Jewish and Christian Scripture

Isa·ias [-əs] -n

  1. isaiah

is·al·lo·bar [(,)ī-'sa-lə-,bär] -n, adj

  1. an imaginary line or a line on a chart connecting the places of equal change of atmospheric pressure within a specified time

ISBN -abbr

  1. International Standard Book Number

ISC -abbr

  1. interstate commerce

is·chae·mia [is-'kē-mē-ə] -n, adj

(variant of ischemia)

  1. deficient supply of blood to a body part (as the heart or brain) that is due to obstruction of the inflow of arterial blood

is·che·mia [is-'kē-mē-ə] -n, adj

  1. deficient supply of blood to a body part (as the heart or brain) that is due to obstruction of the inflow of arterial blood

is·chi·um ['is-kē-əm] -n, adj

  1. the dorsal and posterior of the three principal bones composing either half of the pelvis

ISDN -abbr

  1. integrated services digital network

is·en·tro·pic [,ī-sᵊn-'trō-pik, -'trä-] -adj, adv

  1. of or relating to equal or constant entropy
  2. taking place without change of entropy

Iseult [i-'sült, -'zült] -n

  1. isolde

Ish·ma·el ['ish-(,)mā-əl, -mē-] -n

  1. the outcast son of Abraham and Hagar according to the account in Genesis and a prophet of Islam according to the Koran
  2. a social outcast

Ish·ma·el·ite [-ə-,līt] -n, adj

  1. a descendant of Ishmael
  2. ishmael

isin·glass ['ī-zᵊn-,glas, 'ī-ziŋ-] -n

  1. a semitransparent whitish very pure gelatin prepared from the air bladders of fishes (as sturgeons) and used esp. as a clarifying agent and in jellies and glue
  2. mica esp. when in thin transparent sheets
  3. muscovite

Isis ['ī-səs] -n

  1. an Egyptian nature goddess and wife and sister of Osiris

isl -abbr

  1. island

Is·lam [is-'läm, iz-, -'lam, 'is-,, 'iz-,] -n, adj, n pl but sing or pl in constr

  1. the religious faith of Muslims including belief in Allah as the sole deity and in Muhammad as his prophet
  2. the civilization erected upon Islamic faith
  3. the group of modern nations in which Islam is the dominant religion

Islamic calendar -n

  1. a lunar calendar reckoned from the Hegira in a.d.622 and organized in cycles of 30 years

Islamic era -n

  1. the era used in Muslim countries for numbering Islamic calendar years since the Hegira

Is·lam·ism [is-'lä-,mi-zəm, iz-, -'la-; 'iz-lə-] -n

  1. the faith, doctrine, or cause of Islam
  2. a popular reform movement advocating the reordering of government and society in accordance with laws prescribed by Islam

Is·lam·ize ['iz-lə-,mīz; is-'lä-,mīz, iz-, -'la-] -vt, n

  1. to make Islamic
  2. to convert to Islam

is·land ['ī-lənd] -n

  1. a tract of land surrounded by water and smaller than a continent
  2. : something resembling an island esp. in its isolated or surrounded position: as
  3. a usu. raised area within a thoroughfare, parking lot, or driveway used esp. to separate or direct traffic
  4. a superstructure on the deck of a ship (as an aircraft carrier)
  5. a kitchen counter that is approachable from all sides
  6. an isolated group or area
  7. an isolated ethnological group

island -vt

  1. to make into or as if into an island
  2. to dot with or as if with islands
  3. isolate

is·land·er ['ī-lən-dər] -n

  1. a native or inhabitant of an island

is·landhop ['ī-lənd-,häp] -vi

  1. to travel from island to island in a chain

island universe -n

  1. a galaxy other than the Milky Way

isle ['ī(-ə)l] -n

  1. island
  2. islet
  3. to make an isle of
  4. to place on or as if on an isle

is·let ['ī-lət] -n

  1. a little island
  2. islet of Langerhans

islet of Lang·er·hans [-'läŋ-ər-,hänz, -,hän(t)s]

  1. any of the groups of small slightly granular endocrine cells that form anastomosing trabeculae among the tubules and alveoli of the pancreas and secrete insulin and glucagon

ism ['i-zəm] -n

  1. a distinctive doctrine, cause, or theory
  2. an oppressive and esp. discriminatory attitude or belief
    • we all have got to come to grips with our ism s -- Joycelyn Elders

isn't ['i-zᵊnt, -ᵊn, dial also 'i-dᵊn(t) or 'in(t)]

  1. is not

ISO -abbr

  1. International Organization for Standardization; International Standards Organization

iso·al·lox·a·zine [-ə-'läk-sə-,zēn] -n

  1. a yellow solid C 10H 6N 4O 2that is the precursor of various flavins (as riboflavin)

iso·bar ['ī-sə-,bär] -n

  1. an imaginary line or a line on a map or chart connecting or marking places of equal barometric pressure
  2. one of two or more atoms or elements having the same atomic weights or mass numbers but different atomic numbers

iso·bar·ic [,ī-sə-'bär-ik, -'ber-, -'ba-rik] -adj

  1. of or relating to an isobar
  2. characterized by constant or equal pressure
    • an isobaric process

iso·bu·tane [,ī-sō-'byü-,tān] -n

  1. a gaseous branched-chain hydrocarbon (CH 3) 3CH isomeric with normal butane that is used esp. as a fuel

iso·bu·tyl·ene [-'byü-tə-,lēn] -n

  1. a gaseous butylene C 4H 8used esp. in making butyl rubber and gasoline components

iso·ca·lo·ric [-kə-'lȯr-ik, -'lär-; -'ka-lə-rik] -adj

  1. having similar caloric values
    • isocaloric diets

iso·car·box·az·id [-,kär-'bäk-sə-zəd] -n

  1. an antidepressant drug C 12H 13N 3O 2

iso·chro·mo·some [,ī-sə-'krō-mə-,sōm, -,zōm] -n

  1. a chromosome produced by transverse splitting of the centromere so that both arms are derived from the dyad on one side of the centromere of the parental chromosome and each arm has identical genes arranged in the same order counting away from the centromere

iso·chron ['ī-sə-,krän] -n

  1. an imaginary line or a line on a chart connecting points at which an event occurs simultaneously or which represents the same time or time difference

iso·chro·nal [ī-'sä-krə-nᵊl, ,ī-sə-'krō-] -adj, adv, n

  1. uniform in time : having equal duration : recurring at regular intervals

iso·chro·nous [ī-'sä-krə-nəs, ,ī-sə-'krō-] -adj, adv

  1. isochronal

iso·cit·ric acid [,ī-sə-'si-trik-] -n

  1. a crystalline isomer of citric acid that occurs esp. as an intermediate stage in the Krebs cycle

iso·cy·a·nate [,ī-sō-'sī-ə-,nāt, -nət] -n

  1. an ester of isomeric cyanic acid used esp. in plastics and adhesives

iso·cy·clic [-'sī-klik, -'si-] -adj

  1. having or being a ring composed of atoms of only one element
  2. carbocyclic

iso·di·a·met·ric [-,dī-ə-'me-trik] -adj

  1. having equal diameters

iso·dose ['ī-sə-,dōs] -adj

  1. of or relating to points or zones in a medium that receive equal doses of radiation

iso·elec·tric [,ī-sō-i-'lek-trik] -adj

  1. having or representing zero difference of electric potential
  2. being the pH at which the electrolyte will not migrate in an electric field
    • the isoelectric point of a protein

isoelectric focusing -n

  1. an electrophoretic technique for separating proteins by causing them to migrate under the influence of an electric field through a medium (as a gel) having a pH gradient to locations with pH values corresponding to their isoelectric points

iso·elec·tron·ic [-i-,lek-'trä-nik] -adj, adv

  1. having the same number of electrons or valence electrons

iso·en·zyme [-'en-,zīm] -n, adj

  1. any of two or more chemically distinct but functionally similar enzymes

iso·fla·vone [,ī-sō-'flā-,vōn] -n

  1. a bioactive ketone C 15H 10O 2noted for its numerous derivatives that are found in plants (as the soybean) and have antioxidant and estrogenic activity
  2. any of these derivatives (as daidzein or genistein)

iso·form ['ī-sə-,fȯrm] -n

  1. any of two or more functionally similar proteins that have a similar but not an identical amino acid sequence

iso·ga·mete [,ī-sō-'ga-,mēt also -gə-'mēt] -n, adj

  1. a gamete indistinguishable in form or size or behavior from another gamete with which it can unite to form a zygote

isog·a·mous [ī-'sä-gə-məs] -adj, n

  1. having or involving isogametes

iso·ge·ne·ic [,ī-sō-jə-'nē-ik, -'nā-] -adj

  1. syngeneic
    • an isogeneic graft

iso·gen·ic [-'je-nik] -adj

  1. characterized by essentially identical genes
    • identical twins are isogenic

iso·gloss ['ī-sə-,gläs, -,glȯs] -n, adj

  1. a boundary line between places or regions that differ in a particular linguistic feature
  2. a line on a map representing an isogloss

iso·gon·ic [,ī-sə-'gä-nik] -adj, n

  1. exhibiting equivalent relative growth of parts such that size relations remain constant

isogonic line -n

  1. an imaginary line or a line on a map joining points on the earth's surface at which the magnetic declination is the same called also isogonal

iso·graft ['ī-sə-,graft] -n, vt

  1. a homograft between genetically identical or nearly identical individuals

iso·gram ['ī-sə-,gram] -n

  1. isoline

iso·hy·et [,ī-sō-'hī-ət] -n, adj

  1. a line on a map or chart connecting areas of equal rainfall

iso·la·ble ['ī-sə-lə-bəl also 'i-] -adj

  1. capable of being isolated

iso·late ['ī-sə-,lāt also 'i-] -vt, n

  1. to set apart from others
  2. quarantine
  3. to select from among others
  4. to separate from another substance so as to obtain pure or in a free state
  5. insulate
  6. being alone : solitary, isolated
  7. an individual, population, strain, or culture obtained by or resulting from selection or separation
  8. an individual socially withdrawn or removed from society

isolated -adj

  1. occurring alone or once : unique
  2. sporadic

iso·la·tion [,ī-sə-'lā-shən also ,i-] -n

  1. the action of isolating : the condition of being isolated

iso·la·tion·ism [-shə-,ni-zəm] -n, n or adj

  1. a policy of national isolation by abstention from alliances and other international political and economic relations

Isol·de [i-'zōl-də, -'sōl-] -n

  1. an Irish princess married to King Mark of Cornwall and loved by Tristram
  2. the daughter of the King of Brittany and wife of Tristram

iso·leu·cine [,ī-sō-'lü-,sēn] -n

  1. a crystalline essential amino acid C 6H 13NO 2isomeric with leucine

iso·line ['ī-(,)sō-,līn] -n

  1. a line on a map or chart along which there is a constant value (as of temperature or rainfall)

iso·mer ['ī-sə-mər] -n

  1. one of two or more compounds, radicals, or ions that contain the same number of atoms of the same elements but differ in structural arrangement and properties
  2. a nuclide isomeric with one or more others

isom·er·ase [ī-'sä-mə-,rās, -,rāz] -n

  1. an enzyme that catalyzes the conversion of its substrate to an isomeric form

iso·mer·ic [,ī-sə-'mer-ik] -adj

  1. of, relating to, or exhibiting isomerism

isom·er·ism [ī-'sä-mə-,ri-zəm] -n

  1. the relationship of two or more chemical species that are isomers
  2. the relation of two or more nuclides with the same mass numbers and atomic numbers but different energy states and rates of radioactive decay

isom·er·ize [ī-'sä-mə-,rīz] -vb, n

  1. to become changed into an isomeric form
  2. to cause to isomerize

iso·met·ric [,ī-sə-'me-trik] -adj, adv

  1. of, relating to, or characterized by equality of measure
  2. relating to or being a crystallographic system characterized by three equal axes at right angles
  3. of, relating to, involving, or being muscular contraction (as in isometrics) against resistance, without significant shortening of muscle fibers, and with marked increase in muscle tone

isometric line -n

  1. a line representing changes of pressure or temperature under conditions of constant volume
  2. a line (as a contour line) drawn on a map and indicating a true constant value throughout its extent

iso·met·rics [,ī-sə-'me-triks] -n pl but sing or pl in constr

  1. exercise or a system of exercises in which opposing muscles are so contracted that there is little shortening but a great increase in tone of muscle fibers involved

isom·e·try [ī-'sä-mə-trē] -n

  1. a mapping of a metric space onto another or onto itself so that the distance between any two points in the original space is the same as the distance between their images in the second space
    • rotation and translation are isometries of the plane

iso·mor·phic [,ī-sə-'mȯr-fik] -adj, adv

  1. being of identical or similar form, shape, or structure
    • isomorphic crystals
  2. having sporophytic and gametophytic generations alike in size and shape
  3. related by an isomorphism
    • isomorphic mathematical rings

iso·mor·phism [,ī-sə-'mȯr-,fi-zəm] -n

  1. : the quality or state of being isomorphic: as
  2. similarity in organisms of different ancestry resulting from convergence
  3. similarity of crystalline form between chemical compounds
  4. a one-to-one correspondence between two mathematical sets
  5. a homomorphism that is one-to-one

iso·mor·phous [,ī-sə-'mȯr-fəs] -adj, n

  1. isomorphic

iso·ni·a·zid [,ī-sə-'nī-ə-zəd] -n

  1. a crystalline compound C 6H 7N 3O used in treating tuberculosis

iso·oc·tane [,ī-sō-'äk-,tān] -n

  1. an octane of branched-chain structure or a mixture of such octanes
  2. a flammable liquid octane used in determining the octane number of fuels

iso·pach ['ī-sə-,pak] -n

  1. an isoline that connects points of equal thickness of a geological stratum formation or group of formations

iso·phote ['ī-sə-,fōt] -n, adj

  1. a curve on a chart joining points of equal light intensity from a given source

iso·pi·es·tic [,ī-sō-pē-'es-tik, -pī-] -adj

  1. of, relating to, or marked by equal pressure

iso·pleth ['ī-sə-,pleth] -n, adj

  1. an isoline on a graph showing the occurrence or frequency of a phenomenon as a function of two variables
  2. a line on a map connecting points at which a given variable has a specified constant value

iso·pod ['ī-sə-,päd] -n, adj

  1. any of a large order (Isopoda) of small sessile-eyed aquatic or terrestrial crustaceans with the body composed of seven free thoracic segments each bearing a pair of similar legs

iso·pren·a·line [,ī-sə-'pre-nə-lən] -n

  1. isoproterenol

iso·prene ['ī-sə-,prēn] -n

  1. a flammable liquid unsaturated hydrocarbon C 5H 8used esp. in synthetic rubber

iso·pren·oid [,ī-sə-'prē-,nȯid] -adj, n

  1. relating to, containing, or being a branched-chain grouping characteristic of isoprene

iso·pro·pyl [,ī-sə-'prō-pəl] -n

  1. the alkyl radical isomeric with straight-chain propyl often used in combination

isopropyl alcohol -n

  1. a volatile flammable alcohol C 3H 8O used esp. as a solvent and rubbing alcohol

iso·pro·ter·e·nol [,ī-sə-prō-'ter-ə-,nȯl, -,nōl] -n

  1. a sympathomimetic agent C 11H 17NO 3used in the treatment of asthma

iso·pyc·nic [,ī-sō-'pik-nik] -adj

  1. of, relating to, or marked by equal or constant density
  2. being or produced by a technique (as centrifugation) in which the components of a mixture are separated on the basis of differences in density

isos·ce·les [ī-'säs-,lēz, -'sä-sə-] -adj

  1. having two equal sides
  2. having the two nonparallel sides equal

is·os·mot·ic [,ī-,säz-'mä-tik, -,säs-] -adj, adv

  1. of, relating to, or exhibiting equal osmotic pressure
    • isosmotic solutions

iso·spin ['ī-sə-,spin] -n

  1. a quantum characteristic of a group of closely related subatomic particles (as a proton and a neutron) handled mathematically like ordinary spin with the possible orientations in a hypothetical space specifying the number of particles of differing electric charge comprising the group called also isotopic spin

isos·ta·sy [ī-'säs-tə-sē] -n, adj, adv

  1. general equilibrium in the earth's crust maintained by a yielding flow of rock material beneath the surface under gravitative stress
  2. the quality or state of being subjected to equal pressure from every side

iso·tac·tic [,ī-sə-'tak-tik] -adj

  1. having or relating to a stereochemical regularity of structure in the repeating units of a polymer

iso·therm ['ī-sə-,thərm] -n

  1. a line on a map or chart of the earth's surface connecting points having the same temperature at a given time or the same mean temperature for a given period
  2. a line on a chart representing changes of volume or pressure under conditions of constant temperature

iso·ther·mal [,ī-sə-'thər-məl] -adj, adv

  1. of, relating to, or marked by equality of temperature
  2. of, relating to, or marked by changes of volume or pressure under conditions of constant temperature

iso·thio·cy·a·nate [,ī-sō-,thī-ō-'sī-ə-,nāt] -n

  1. a compound containing the monovalent group NCS

iso·ton·ic [,ī-sə-'tä-nik] -adj, adv, n

  1. of, relating to, or being muscular contraction in the absence of significant resistance, with marked shortening of muscle fibers, and without great increase in muscle tone
  2. isosmotic used of solutions

iso·tope ['ī-sə-,tōp] -n, adj, adv

  1. any of two or more species of atoms of a chemical element with the same atomic number and nearly identical chemical behavior but with differing atomic mass or mass number and different physical properties
  2. nuclide

isotopic spin -n

  1. isospin

iso·tret·i·noin [,ī-sō-'tre-tə-,nȯin] -n

  1. a cis isomer of retinoic acid that is a synthetic derivative of vitamin A, inhibits sebaceous gland function and keratinization, and is used in the treatment of severe inflammatory acne

iso·tro·pic [,ī-sə-'trō-pik, -'trä-] -adj, n

  1. exhibiting properties (as velocity of light transmission) with the same values when measured along axes in all directions
    • an isotropic crystal

iso·zyme ['ī-sə-,zīm] -n, adj

  1. isoenzyme

ISP -abbr

  1. Internet service provider

Isr -abbr

  1. Israel; Israeli

Is·ra·el ['iz-rē-əl, -(,)rā- also 'is- or 'iz-rəl] -n, adj

  1. jacob
  2. the Jewish people
  3. a people chosen by God

Is·rae·li [iz-'rā-lē also ,iz-rə-'ā-lē] -adj

  1. of or relating to the people or the republic of Israel

Israeli -n

  1. a native or inhabitant of the republic of Israel

Is·ra·el·ite ['iz-r(ē-)ə-,līt] -n

  1. a descendant of the Hebrew patriarch Jacob
  2. a native or inhabitant of the ancient northern kingdom of Israel

Israelite -adj

  1. of or relating to Israel or to the Israelites

Is·sa·char ['i-sə-,kär] -n

  1. a son of Jacob and the traditional eponymous ancestor of one of the tribes of Israel

is·sei [(,)ē-'sā, 'ē-,sā] -n

  1. a Japanese immigrant esp. to the U.S.

ISSN -abbr

  1. International Standard Serial Number

is·su·able ['i-shü-ə-bəl] -adj, adv

  1. open to contest, debate, or litigation
  2. authorized for issue
    • bonds issuable under the merger terms
  3. possible as a result or consequence

is·su·ance ['i-shə-wən(t)s, -shü-ən(t)s] -n

  1. issue
  2. issue

is·su·ant [-wənt, -ənt] -adj

  1. rising with only the upper part visible
  2. coming forth : emerging

is·sue ['i-(,)shü, chiefly Southern 'i-shə, chiefly Brit 'is-(,)yü] -n, adj

  1. proceeds from a source of revenue (as an estate)
  2. the action of going, coming, or flowing out : egress, emergence
  3. a means or place of going out : exit, outlet
  4. offspring, progeny
    • died without issue
  5. a final outcome that usu. constitutes a solution (as of a problem) or resolution (as of a difficulty)
  6. a final conclusion or decision about something arrived at after consideration
  7. termination, end
    • hope that his enterprise would have a prosperous issue -- T. B. Macaulay
  8. a matter that is in dispute between two or more parties
  9. a vital or unsettled matter
    • economic issue s
  10. concern, problem
    • I have issue s with his behavior
  11. the point at which an unsettled matter is ready for a decision
    • brought the matter to an issue
  12. a discharge (as of blood) from the body
  13. something coming forth from a specified source
    • issue s of a disordered imagination
  14. deed
  15. the act of publishing or officially giving out or making available
    • the next issue of commemorative stamps
    • issue of supplies by the quartermaster
  16. the thing or the whole quantity of things given out at one time
    • read the latest issue

issue -vb, n

  1. to go, come, or flow out
  2. to come forth : emerge
  3. accrue
    • profits issuing from the sale of the stock
  4. to descend from a specified parent or ancestor
  5. to be a consequence or final outcome : emanate, result
  6. to appear or become available through being officially put forth or distributed
  7. eventuate, terminate
  8. to cause to come forth : discharge, emit
  9. to put forth or distribute usu. officially
    • government issued a new airmail stamp
    • issue orders
  10. to send out for sale or circulation : publish
  11. provide , supply

isth -abbr

  1. isthmus

isth·mi·an ['is-mē-ən] -n

  1. a native or inhabitant of an isthmus
  2. a native or inhabitant of the Isthmus of Panama

isthmian -adj

  1. : of, relating to, or situated in or near an isthmus: as
  2. of or relating to the Isthmus of Corinth in Greece or the games held there in ancient times
  3. of or relating to the Isthmus of Panama connecting the No. American and So. American continents

isth·mic ['is-mik] -adj

  1. of or relating to an anatomical isthmus

isth·mus ['is-məs] -n

  1. a narrow strip of land connecting two larger land areas
  2. a narrow anatomical part or passage connecting two larger structures or cavities

is·tle ['ist-lē] -n

  1. a strong fiber (as for cordage or basketwork) obtained from various tropical American plants (as an agave)

ISV -abbr

  1. International Scientific Vocabulary