A- (3) prefix meaning "not," from Gk a-, an- "not," from pie base *ne "not" (see un-)

deception --- c.1412, from pp. stem of L. decipere (see deceive).

decibel --- 1928, coined from L. decibus "tenth," from decem "ten" + bel unit for measuring sound, after Alexander Graham Bell.

decide --- c.1380, from O.Fr. decider, from L. decidere "to decide," lit. "to cut off," from de- "off" + cædere "to cut" (see cement). Sense is of resolving difficulties "at a stroke." Originally "to settle a dispute;" meaning "to make up one's mind" is attested from 1830. Decided in the adj. sense of "resolute" is from 1790. Decisive is 1611. A decided victory is one whose reality is not in doubt; a decisive one goes far toward settling some issue.

deciduous --- 1688, from L. deciduus "that which falls off," from decidere "to fall off," from de- "down" + cadere "to fall" (see case (1)). Originally with reference to leaves, petals, teeth, etc.; specific sense of "trees whose leaves fall off" (opposed to evergreen) is from 1778.

decimal --- 1608, from M.L. decimalis "of tithes or tenths," from L. decimus "tenth," from decem "ten." Applied to Arabic notation before modern sense of "decimal fractions" emerged.

decimation --- 1549, from L.L. decimationem, from L. decimare "the removal or destruction of one-tenth," from decem "ten." Killing one in ten, chosen by lots, from a rebellious city or a mutinous army was a common punishment in classical times. Earliest sense in Eng. was of a tithe; decimate has been used (incorrectly, to the irritation of pedants) since 1663 for "destroy a large portion of."

decipher --- 1528, from de- + cipher.

decision --- c.1454, from M.Fr. decision, from L. decisionem (nom. decisio), see decide.

decisive --- 1611, see decide.

deck (n.) --- 1466, probably aphetic of M.L.G. verdeck, a nautical word, from ver- "fore" + decken "to cover, put under roof," from P.Gmc. *thackjam (related to thatch), from PIE *(s)tog-/*(s)teg- "cover" (see stegosaurus). Sense extended early in Eng. from "covering" to "platform of a ship." "Pack of cards" is 1593, perhaps because they were stacked like decks of a ship. The verb sense of "knock down" is first recorded c.1953, probably from notion of laying someone out on the deck. Deck chair (1884) so called because they were used on ocean liners. Tape deck (1949) is in ref. to the flat surface of old reel-to-reel tape recorders.

deck (v.) --- adorn (as in deck the halls), c.1500, from M.Du. dekken "to cover," from the same P.Gmc. root as deck (n.). Replaced O.E. þeccan.

declaim --- c.1385, from L. declamare, from de- intens. prefix + clamare "to cry, shout" (see claim). At first in Eng. spelled declame, but altered under infl. of claim.

declare --- c.1325, from L. declarare "make clear," from de- intensive prefix + clarare "clarify," from clarus "clear."

declasse --- 1887, from Fr. déclassé, pp. of déclasser "to cause to lose class."

declassify --- 1865, originally a term in logic; with reference to state secrets, 1946; from de- + classify.

decline --- c.1327, "to turn aside, deviate," from O.Fr. decliner "to bend, turn aside," from L. declinare "to bend from, inflect," from de- "from" + clinare "to bend," from PIE *klei-n-, suffixed form of *klei "to lean" (see lean (v.)). Sense has been altered since 15c. by interpretation of de- as "downward." Meaning "not to consent" is from 1631. Astronomical declination (c.1386) and grammatical declension (1565) are both ult. from L. noun derivative declinatio.

declivity --- 1612, from L. declivitatem (nom. declivitas), from declivis "a sloping downward," from de- "down" + clivus "a slope," from PIE *klei-wo-, suffixed form of *klei "to lean" (see lean (v.)).

decoction --- 1398, from pp. stem of L. decoquere "to boil down," from de- + coquere "to cook" (see cook (n.)). Decoct is attested from c.1420.

decolletage --- 1894, from décolleté "low-necked" (1831), from Fr. décolleter "to bare the neck and shoulders," from des- "from" + collet, dim. of col (L. collum) "neck" (see collar).

decolonization --- 1938, from de- + colonization.

decommission --- 1922, originally with reference to warships, from de- + commission (v.).

decompose --- 1762, from de- + compose. Sense of "putrefy" is first recorded 1777.

decompress --- 1905, from de- + compress.

decongestant --- 1950, from de- + congestant (see congest).

deconstruction --- 1973, as a strategy of critical analysis, in translations from Fr. of the works of philosopher Jacques Derrida (b.1930).

decontaminate --- 1936, from de- + contaminate. Originally in reference to poison gas.

decor --- 1897, from Fr. décor, from L. decor "beauty, elegance," from decere (see decorate).

decorate --- 1460, from L. decoratus, pp. of decorare "to decorate," from decus (gen. decoris) "an ornament," from PIE base *dek- "to receive, be suitable" (see decent). Decoration in the sense of "star, cross, medal, or other badge of honor" is from 1816. Decorative is from 1791; decorator is first recorded 1755.

decorum --- 1568, from L. neuter of decorus "fit, proper," from decor (see decor). Decorous is attested from 1664.

decoupage --- 1960, from Fr., lit. "the act of cutting out," from decouper "to cut out," from de- "out" + couper "to cut."

decoy --- 1618, most likely from Du. kooi "cage," used of a pond surrounded by nets, into which wildfowl were lured for capture, from W.Gmc. *kaiwa, from L. cavea, "cage." The first element is possibly the Du. definite article de, mistaken in Eng. as part of the word. But decoy, of unknown origin, was the name of a card game popular c.1550-1650, and this may have influenced the form of the word.

decrease --- 1383, from O.Fr. pp. stem of descreistre, from L. decrescere, from de- "away from" + crescere "to grow" (see crescent).

decree --- 1303, from O.Fr. decre, variant of decret, from L. decretum, neut. of decretus, pp. of decernere "to decree, decide, pronounce a decision," from de- + cernere "to separate" (see crisis).

decrepit --- c.1450, from M.Fr. decrepit, from L. decrepitus, from de- "down" + *crepitus, pp. of crepare "to crack, break."

decriminalization --- 1945, from de- + criminal + ization. Especially in reference to narcotics since c.1968.

decry --- 1617, from Fr. decrier, from O.Fr. descrier "cry out, announce," from de- "down, out" + crier "to cry." In Eng., the sense has been colored by the presumption that de- in this word means "down."

dedicate --- c.1386, from L. dedicatus, pp. of dedicare "consecrate, proclaim, affirm," from de- "away" + dicare "proclaim," from stem of dicere "to speak, to say" (see diction). Dedicated "devoted to one's aims or vocation" is first attested 1944.

deduce --- 1410, from L. deducere "lead down, derive" (in M.L. "infer logically"), from de- "down" + ducere "to lead" (see duke). Originally literal, sense of "draw a conclusion from something already known" is first recorded 1529, from M.L.

deduct --- 1419, from L. deductus, pp. of deducere "lead down, bring away;" see deduce, with which it formerly was interchangeable. Technically, deduct refers to taking away portions or amounts; subtract to taking away numbers.

deed --- O.E. dæd "a doing, act," from P.Gmc. *dædis, related to "do," from PIE *dhetis, from *dhe-/*dho- "place, put." Sense of "written legal document" is c.1300.

Deely-bobber --- a headband with springs carrying ornaments, 1982 trademark name held by Ace Novelty Company. Earlier it had been a patent name for a type of building blocks, manufactured 1969-1973.

deem --- O.E. deman, from base of dom (see doom). Originally "to pronounce judgment" as well as "to form an opinion." The two judges of the Isle of Man were called deemsters in 17c.

deemphasize --- 1938, from de- + emphasize.

deep --- O.E. deop, from P.Gmc. *deupaz, from PIE *d(e)u- "deep, hollow" (cf. O.C.S. duno "bottom, foundation," O.Ir. domun "world," via sense development from "bottom" to "foundation" to "earth" to "world"). Figurative sense was in O.E.; extended 16c. to color, sound. Deep pocket "wealth" is from 1951. Deep-freeze was a registered trademark (U.S. Patent Office, 1941) of a type of refrigerator; used generically for "cold storage" since 1949. To go off the deep end "lose control of oneself" is slang first recorded 1921, probably in reference to the deep end of a swimming pool, where a person on the surface can no longer touch bottom. When 3-D films seemed destined to be the next wave and the biggest thing to hit cinema since "talkies," they were known as deepies (1953). The gods have spared us.

deep six (v.) --- discard, 1940s, originally from nautical slang, perhaps from earlier underworld sense of "the grave" (1929), perhaps a reference to the usual grave depth of six feet.

deer --- O.E. deor "animal, beast," from P.Gmc. *deuzan, the general Gmc. word for "animal" (as opposed to man), but often restricted to "wild animal" (cf. O.N. dyr, O.H.G. tior, Ger. Tier, Goth. dius), from PIE *dheusom "creature that breathes," from *dheus- (cf. Lith. dusti "gasp," dvesti "gasp, perish;" O.C.S. dychati "breathe;" cf. L. animal from anima "breath"), from base *dheu-. Sense specialization to a specific animal began in O.E. (usual O.E. for what we now call a deer was heorot), common by 15c., now complete. Probably via hunting, deer being the favorite animal of the chase (cf. Skt. mrga- "wild animal," used especially for "deer"). Deer-lick is first attested 1778, in an American context; deerskin is from 1396.

def --- excellent, first recorded 1979 in Black English, perhaps a shortened form of definite (see define), or from a Jamaican variant of death.

deface --- c.1325, from O.Fr. defacier, from des- "away from" + face "face."

defalcation --- 1476, from M.L. defalcationem, from defalcare, from de- + L. falx "pruning hook."

defame --- 1303, from O.Fr. defamer, from M.L. defamare, from L. diffamare "to spread abroad by ill report," from dis- suggestive of ruination + fama "a report, rumor."

default --- c.1225, "failure, failure to act," from O.Fr. defaute, from M.L. defalta "a deficiency or failure," from L. dis- "away" + fallere "to be wanting." The financial sense is first recorded 1858; the computing sense is from 1966.

defeat --- c.1374, from Anglo-Norm. defeter, from O.Fr. defait, pp. of defaire, from V.L. *diffacere "undo, destroy," from L. dis- "un-, not" + facere "to do, perform" (see factitious). Original sense was of "bring ruination, cause destruction." Military sense of "conquer" is c.1600. Defeatism, defeatist are 1918, from Fr. défaitiste, in reference to the Russians.

defecate --- 1575, "to purify," from L. defæcatus, pp. of defæcare "cleanse from dregs, purify," from the phrase de fæce "from dregs," pl. fæces "feces." Excretory sense first recorded 1830 (defecation), Amer.Eng., from Fr.

defect (n.) --- c.1420, from L. defectus "failure, revolt," from pp. of deficere "to fail, desert" (see deficient). Defection "falling away from a leader, party, or cause" is first recorded 1546, originally of faith. Defective was a euphemism for "mentally ill" from 1898 to c.1935.

defend --- c.1250, from O.Fr. defendre, from L. defendere "ward off, protect," from de- "from, away" + fendere "to strike, push." In the Mercian hymns, L. defendet is glossed by O.E. gescildeð. Defendant is from O.Fr. prp of defendre.

defenestration --- 1620, "the action of throwing out of a window," from L. fenestra "window." A word invented for one incident: the "Defenestration of Prague," May 21, 1618, when two Catholic deputies to the Bohemian national assembly and a secretary were tossed out the window (into a moat) of the castle of Hradshin by Protestant radicals. It marked the start of the Thirty Years War. Some linguists link fenestra with Gk. verb phainein "to show;" others see in it an Etruscan borrowing, based on the suffix -(s)tra, as in L. loan-words aplustre "the carved stern of a ship with its ornaments," genista "the plant broom," lanista "trainer of gladiators."

defense --- 1297, from O.Fr. defens, from L. defensum "thing protected or forbidden," from neut. pp. of defendere "ward off, protect" (see defend). First used 1935 as a euphemism for "national military resources."

defer (1) --- delay, c.1375, from O.Fr. differer, from L. differre "set apart, put off, delay," also "be different, differ," from dis- "apart" + ferre "carry" (see infer). Etymologically identical with differ; the spelling and pronunciation differentiated from 15c., partly by association of this word with delay.

defer (2) --- yield, 1479, from M.Fr. deferer, from L. deferre "carry away, transfer, grant;" modern sense is from meaning "refer (a matter) to someone," from de- "down, away" + ferre "carry" (see infer). Deferential is from 1880.

defiance --- c.1300, from O.Fr. defiance "challenge," from defiant, prp. of defier (see defy).

defibrillation --- 1940, in reference to heartbeat, from fibrillating "beating in an abnormal way," from Mod.L. fibrilla, dim. of fibra "fiber," in reference to the muscle strands of the heart that contract irregularly in this condition.

deficient --- 1581, from L. deficientem (nom. deficiens), prp. of deficere "to desert, fail," from de- "down, away" + facere "to do, perform" (see factitious).

deficit --- 1782, from Fr. deficit (1690), from L. deficit "it is wanting," an introductory word in clauses of inventory, third pers. sing. pres. indicative of deficere "to be deficient" (see deficient).

defile (n.) --- narrow passage, 1685, from Fr. défilé, n. use of pp. of défiler "march by files."

defile (v.) --- make filthy, c.1280, from O.Fr. defouler "trample down, violate," from de- "down" + fouler "to tread," from L. fullo "person who cleans and thickens cloth by stamping on it." Sense infl. by foul (q.v.); spelling infl. by obsolete native befile, which it replaced and which meant about the same thing.

define --- c.1384, from O.Fr. definir "to end, terminate, determine," from L. definire "to limit, determine, explain," from de- "completely" + finire "to bound, limit," from finis "boundary, end" (see finish). Definite (1553) means "defined, clear, precise, unmistakable;" definitive (c.1386) means "having the character of finality." Definition is recorded from 1645 as a term in logic; the "meaning of a word" sense is from 1551.

deflate --- 1891, in reference to balloons, coinage based on inflate. L. deflare meant "to blow away," but in the modern word the prefix is taken in the sense of "down." Deflation in reference to currency or economic situations is from 1920.

deflect --- c.1555, from L. deflectere "to bend aside or downward," from de- "away" + flectere "to bend." Originally transitive, the intrans. sense is first recorded 1646.

deflower --- 1382, from O.Fr. desflorer (13c.), from L. deflorare from flos "flower" (see flora). Notion is "to strip of flowers," hence "to ravish," which is the original sense in Eng. "The French Indians are said not to have deflowered any of our young women they captivated." [1775]

defogger --- 1966, from de- + fog + -er.

defoliation --- 1659, from L.L. defoliatus, pp. of defoliare "shed leaves." Defoliant is from 1943.

deform --- c.1400, from O.Fr. deformer, from L. deformare "put out of shape, disfigure."

defraud --- 1362, from O.Fr. defrauder, from L. defraudare (see fraud). Prefix de- used here in the sense of "thoroughly."

defray --- 1543, from M.Fr. defraier, from des- "out" + fraier "spend," from O.Fr. frais "costs, damages caused by breakage," from L. fractum, neuter pp. of frangere "to break" (see fraction). Alternate etymology traces second element to O.H.G. fridu "peace."

deft --- O.E. gedæfte "mild, gentle," differentiated in M.E. into daft (q.v.) and this word, via sense of "apt, skillful, adept."

defunct --- 1548, from L. defunctus "dead," lit. "off-duty," from pp. of defungi "to discharge, finish," from de- "off, completely," + fungi "perform or discharge duty."

defy --- c.1300, from O.Fr. defier, from V.L. *disfidare "renounce one's faith," from L. dis- "away" + fidus "faithful." Meaning shifted 14c. from "be disloyal" to "challenge."

degenerate (adj.) --- 1494, from L. degeneratus, pp. of degenerare "depart from one's kind, fall from ancestral quality," from phrase de genere, from genus (gen. generis) "birth, descent" (see genus). The verb is from 1545; the noun is 1555.

degrade --- c.1325, from O.Fr. degrader (12c.), from des- "down" + L. gradus "step" (see grade).

degree --- c.1230, from O.Fr. degre "a degree, step, rank," from V.L. *degradus "a step," from L.L. degredare, from L. de- "down" + gradus "step" (see grade). Most modern senses date from M.E., from notion of a hierarchy of steps. Meaning "a grade of crime" is 1676; that of "a unit of temperature" is from 1727. The division of the circle into 360 degrees is very ancient and was known in Babylon and Egypt. It is perhaps from the daily motion of the sun through the zodiac in the course of a year.

dehumanize --- 1818 (see human).

dehydrate --- 1854, from Gk. hydor "water" (see water (n.1)). A chemical term at first, given a broader extension 1880s.

deify --- c.1340, from O.Fr. deifier, from L.L. deificare, from deificus "making godlike," from L. deus "god" + facere "to make, do" (see factitious).

deign --- 1297, from O.Fr. deignier, from L. dignari "to deem worthy or fit," from dignus "worthy" (see dignity). Sense of "take or accept graciously" led to that of "condescend" (1589).

deism --- 1682 (deist is from 1621), from Fr. déisme, from L. deus "god" (see Zeus). Until c.1700, opposed to atheism, in a sense where we would now use theism (see theist).

deity --- c.1300, from O.Fr. deite, from L.L. deitatem (nom. deitas) "divine nature," coined by Augustine from L. deus "god," from PIE *deiwos (see Zeus).

déjà vu --- 1903, from Fr., "already seen." Also known as promnesia. Similar phenomena are déjà entendu "already heard" (of music, etc.), 1965; and déjà lu "already read."

deject --- 1430, from L. dejectus, pp. of deicere "to cast down," from de- "down" + -icere, comb. form of jacere "to throw." Originally literal; the sense of "depress in spirit" is c.1450.

deke --- 1960, ice hockey slang for a quick feinting move, short for decoy. The verb is attested from 1961.

Delaware --- U.S. state, river, Indian tribe, named for the bay, which was named for Baron (commonly "Lord") De la Warr (Thomas West, 1577-1618), first Eng. colonial governor of Virginia. The family name is attested from 1201, from Delaware in Brasted, Kent, probably ult. from de la werre "of the war" (a warrior), from O.Fr. werre/guerre "war."

delay --- c.1275, from O.Fr. delaier, from de- "away, from" + laier "leave, let," probably a variant of L. laissier, from L. laxare "slacken, undo."

delectable --- c.1400, from O.Fr. delectable, from L. delectabilis, from delectare (see delight).

delegate (n.) --- c.1380, from L. delegatus, pp. of delegare "to send as a representative," from de- "from, away" + legare "send with a commission." The verb is from 1530.

delete --- 1495, from L. deletus, pp. of delere "destroy, blot out, efface," from delevi, originally perf. tense of delinere "to daub, erase by smudging," from de- "from, away" + linere "to smear, wipe."

deleterious --- 1643, from Gk. deleterios, from deleter "destroyer," from deleisthai "to hurt, injure."

delftware --- 1714, from Delft, town in Holland where the glazed earthenware was made; the town named from its chief canal, from Du. delf, lit. "ditch, canal;" which is related to O.E. dælf and modern delve.

Delian --- 1623, "of Delos, tiny Gk. island in the Aegean, birthplace of Apollo and Artemis. Delian problem "find the length of the side of a cube having double the volume of a given cube," was set by the oracle at Delos when it answered (430 B.C.E.) than the plague in Athens would end when Apollo's (cube-shaped) altar was doubled.

deliberation --- c.1374, from L. deliberationem, from deliberare "weigh, consider well," from de- "entirely" + -liberare, alt. (perhaps by influence of liberare "liberate") from librare "to balance, weigh," from libra "scale." The verb deliberate is attested from 1552; the adj. meaning "done with careful consideration" is from 1548; the meaning "slow, consciously unhurried" is attested by 1596.

delicate --- c.1374, from L. delicatus "alluring, delightful, dainty," also "addicted to pleasure," of unknown origin; related by folk etymology (and perhaps genuinely) to deliciæ "a pet," and delicere "to allure, entice." Meaning "feeble in constitution" is c.1400; that of "easily broken" is recorded from 1568. Delicacy "a dainty viand" is from 1450.

delicatessen --- 1889, Amer.Eng. borrowing from Ger. delikatessen, pl. of delikatesse "a delicacy, fine food," from Fr. delicatesse (1564), from delicat "fine," from L. delicatus (see delicate). Shortened form deli first recorded 1954.

delicious --- c.1300, from O.Fr. delicieus, from L.L. deliciosus "delicious, delicate," from L. delicia (pl. deliciæ) "a delight," from delicere "to allure, entice," from de- "away" + lacere "lure, deceive." As a name of a type of apple, attested from 1903, first grown by Jesse Hiatt of Iowa, U.S.A. Colloquial shortening delish is attested from 1920.

delight --- c.1225, delit, from O.Fr. delit, from delitier "please greatly, charm," from L. delectare "to allure, delight," freq. of delicere "entice" (see delicious). Spelled delite until 16c. when it changed under infl. of light, flight, etc.

delineate --- 1559, from L. delineatus, pp. of delineare, from de- "completely" + lineare "draw lines," from linea "line."

delinquent --- 1484, from L. delinquentum (nom. delinquens), prp. of delinquere, from de- "completely" + linquere "to leave" (see relinquish). The adj. and noun are equally old in Eng.

delirium --- 1599, from L. delirium "madness," from deliriare "be crazy, rave," lit. "go off the furrow," a plowing metaphor, from phrase de lire (de "off, away" + lira "furrow"). Delirium tremens is Mod.L., "trembling delirium," introduced 1813 by British physician Thomas Sutton, for "that form of delirium which is rendered worse by bleeding, but improved by opium. By Rayer and subsequent writers it has been almost exclusively applied to delirium resulting from the abuse of alcohol" [Sydenham Society Lexicon of Medicine].

deliver --- c.1225, from O.Fr. delivrer, from L.L. deliberare, from L. de- "away" + liberare "to free" (see deliberation). Sense of "hand over" is c.1280, which brings it in opposition to its root. Meaning "bring to childbirth" (unburden) is c.1300; that of "project, throw" is 1597. Delivery "manner of utterance" is from 1667.

dell --- O.E. dell (perhaps lost and then borrowed in M.E. from cognate M.Du./M.L.G. delle), from P.Gmc. *daljo, related to dale. Uncertain relationship to dell, rogue's cant 16c.-17c. for "a young girl of the vagrant class." "A Dell is a yonge wenche, able for generation, and not yet knowen ... by the vpright man" [Thomas Harman, 1567].

Della Crusca --- 1796, from It. Accademia della Crusca, lit. "Academy of the Chaff," "the name of an Academy established at Florence in 1582, mainly with the object of sifting and purifying the Italian language; whence its name, and its emblem, a sieve" [OED].

Della Robbia --- 1787, from name of a family of 15c. It. painters and sculptors, used of wares made by Luca Della Robbia, or those like them.

delouse --- 1919, from de- + louse; first used in reference to World War I armies.

delta --- c.1200, Gk. letter shaped like a triangle, equivalent to our "D," the name from Phoenician daleth "tent door." Herodotus used it of the mouth of the Nile, and it was so used in Eng. from 1555; applied to other river mouths from 1790. Deltoid muscle so called since 1741, from its shape.

delude --- c.1408, from L. deludere "to mock, deceive," from de- "down, to one's detriment" + ludere "to play" (see ludicrous).