deflower (v.) Look up deflower at
late 14c., "deprive (a maiden) of her virginity," also "excerpt the best parts of (a book)," from Old French desflorer (13c., Modern French déflorer) "to deflower (a garden); to take the virginity of," from Late Latin deflorare, from de- (see de-) + flos "flower" (see flora). Notion is "to strip of flowers," hence "to ravish," which is the oldest sense in English.
The French Indians are said not to have deflowered any of our young women they captivated. [James Adair, "The Life of an Indian Trader," London, 1775]
defogger (n.) Look up defogger at
1966, from agent noun from de- + fog (v.).
defoliant (adj.) Look up defoliant at
1943, from defoliate + -ant.
defoliate (v.) Look up defoliate at
1793, perhaps a back-formation from defoliation. Earlier in this sense was defoil (c. 1600). Related: Defoliated; defoliating.
defoliation (n.) Look up defoliation at
1650s, noun of action from past participle stem of Late Latin defoliare "shed leaves," from de- (see de-) + folium "leaf" (see folio).
deforest (v.) Look up deforest at
1880 in modern sense, from de- + forest. Related: Deforested; deforesting. Disforest in the sense "to clear of trees" is from 1660s. Disafforest is attested in this sense from 1842; originally it meant "reduce from the legal status of a forest" (1590s).
deforestation (n.) Look up deforestation at
1884, from deforest + -ation. Earlier was deforesting (1530s) which was a legal term for the change in definition of a parcel of land from "forest" to something else.
deform (v.) Look up deform at
c. 1400, "to disfigure," from Old French deformer (13c.), from Latin deformare "put out of shape, disfigure," from de- (see de-) + formare (see form (v.)). Related: Deformed; deforming.
deformation (n.) Look up deformation at
mid-15c., "transformation," from Old French deformation and directly from Latin deformationem (nominative deformatio), noun of action from past participle stem of deformare (see deform).
deformity (n.) Look up deformity at
early 15c., diformyte, from Old French deformité "deformity, disfigurement," from Latin deformitatem (nominative deformitas) "ugliness," from deformis "misformed, misshapen," from deformare (see deform).
defragment (v.) Look up defragment at
1992, in computer sense, from de- + fragment. Related: Defragmented; defragmenting.
defraud (v.) Look up defraud at
mid-14c., from Old French defrauder, from Latin defraudare "to defraud, cheat," from de- "thoroughly" (see de-) + fraudare "to cheat, swindle" (see fraud). Related: Defrauded; defrauding.
defray (v.) Look up defray at
1540s, from Middle French defraier (15c.), perhaps from de- "out" (see de-) + fraier "spend," from Old French frais "costs, damages caused by breakage," from Latin fractum, neuter past participle of frangere "to break" (see fraction). Alternative etymology traces second element to Old High German fridu "peace," via Vulgar Latin *fredum "fine, cost."
defrock (v.) Look up defrock at
1580s, from French défroquer (15c.), from de- (see de-) + froque "frock" (see frock). Related: Defrocked. A Modern English verb frock "supply with a frock" is attested only from 1828 and probably is a back-formation from this.
defrost (v.) Look up defrost at
1895, from de- + frost. Related: Defrosted; defrosting.
deft (adj.) Look up deft at
Old English gedæfte "mild, gentle," differentiated in Middle English into daft (q.v.) and this word, via sense of "apt, skillful, adept." Cognate with Gothic gadaban "to be fit," Old Norse dafna "to grow strong," Dutch deftig "important, relevant."
deftly (adv.) Look up deftly at
mid-15c., from deft + -ly (2).
defunct (adj.) Look up defunct at
1590s, from Old French defunct (14c., Modern French defunt) or directly from Latin defunctus "dead," literally "off-duty," from past participle of defungi "to discharge, finish," from de- "off, completely" (see de-) + fungi "perform or discharge duty," from PIE root *bheug- (2) "to enjoy" (see brook (v.)).
defuse (v.) Look up defuse at
1943, from de- + fuse. Related: Defused; defusing.
defy (v.) Look up defy at
c. 1300, "to renounce one's allegiance;" mid-14c., "to challenge, defy," from Old French defier, desfier "to challenge, defy, provoke; renounce (a belief), repudiate (a vow, etc.)," from Vulgar Latin *disfidare "renounce one's faith," from Latin dis- "away" (see dis-) + fidus "faithful," from the same root as fides "faith" (see faith).
degauss (v.) Look up degauss at
"de-magnetize," originally especially of ships as a defense against magnetic mines, 1940, from German scientist Carl Friedrich Gauss (1777-1855), a pioneer in the study of magnetics.
degeneracy (n.) Look up degeneracy at
1660s, from degenerate + -cy.
degenerate (adj.) Look up degenerate at
late 15c., from Latin degeneratus, past participle of degenerare "to be inferior to one's ancestors, to become unlike one's race or kind, fall from ancestral quality," used of physical as well as moral qualities, from phrase de genere, from de + genus (genitive generis) "birth, descent" (see genus). The noun is from 1550s.
degenerate (v.) Look up degenerate at
1540s, from Latin degeneratus, past participle of degenerare "fall from ancestral quality" (see degenerate (adj.)). Figurative sense of "to fall off, decline" was in Latin. Related: Degenerated; degenerating.
degeneration (n.) Look up degeneration at
c. 1600, from French dégéneration (15c.) or directly from Late Latin degenerationem (nominative degeneratio), noun of action from past participle stem of Latin degenerare (see degenerate (adj.)).
degenerative (adj.) Look up degenerative at
1846; see degenerate + -ive.
deglutition (n.) Look up deglutition at
from French déglutition (16c.), from Latin deglutitionem, noun of action from past participle stem of deglutare, from de- (see de-) + glutire "to swallow," from PIE *gwele- (3) "to swallow" (see gullet).
degradation (n.) Look up degradation at
1530s, from French dégradation (14c., Old French degradacion), from Medieval Latin degradationem (nominative degradatio), noun of action from past participle stem of degradare (see degrade).
degrade (v.) Look up degrade at
late 14c., from Old French degrader (12c.) "degrade, deprive (of office, rank, etc.)," from des- "down" (see dis-) + Latin gradus "step" (see grade (n.)). Related: Degraded; degrading.
degree (n.) Look up degree at
early 13c., from Old French degré (12c.) "a step (of a stair), pace, degree (of relationship), academic degree; rank, status, position," said to be from Vulgar Latin *degradus "a step," from Late Latin degredare, from Latin de- "down" (see de-) + gradus "step" (see grade (n.)).

Most modern senses date from Middle English, from notion of a hierarchy of steps. Meaning "a grade of crime" is 1670s; that of "a unit of temperature" is from 1727. The division of the circle into 360 degrees 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.
degression (n.) Look up degression at
late 15c., from Latin degressionem (nominative degressio) "a going down," noun of action from past participle stem of degredi "to go down, march down, descend," from de- "down" (see de-) + gradus "step" (see grade (n.)).
degustation (n.) Look up degustation at
1650s, from Latin degustationem (nominative degustatio) "a tasting," noun of action from past participle stem of degustare "to take a taste from, sample," from de- (see de-) + gustare "to taste" (see gusto).
dehiscence (n.) Look up dehiscence at
1828, from Modern Latin dehiscentia, from dehiscentem (nominative dehiscens), present participle of dehiscere "to gape, open, split down" (of the earth, etc.), from de- (see de-) + hiscere, inchoative of hiare "to yawn" (see yawn (v.)).
dehumanize (v.) Look up dehumanize at
1818, from de- + humanize. Related: Dehumanized; dehumanizing.
dehumidifier (n.) Look up dehumidifier at
1921, agent noun from de- + humidify.
dehydrate (v.) Look up dehydrate at
1854, from de- + hydrate (v.). A chemical term at first, given a broader extension 1880s. Related: Dehydration (1834).
deicide (n.) Look up deicide at
1610s, "the killing of a god;" 1650s, "one who kills a god," from Latin deus "god" (see Zeus) + -cida (see -cide).
deictic (adj.) Look up deictic at
1828, from Latinized form of Greek deiktikos "able to show," from deiktos "shown," verbal adjective from deiknynai "to show" (see diction).
deific (adj.) Look up deific at
late 15c., from French déifique (late 14c.), from Late Latin deificus "god-making, sacred," in Medieval Latin "divine," from deus "god" (see Zeus) + -ficus "making," from unstressed form of facere "to make, do" (see factitious).
deification (n.) Look up deification at
late 14c., from Late Latin deificationem (nominative deificatio), noun of action from past participle stem of deificare (see deify).
deify (v.) Look up deify at
mid-14c., from Old French deifier (13c.), from Late Latin deificare, from deificus "making godlike," from Latin deus "god" (see Zeus) + -ficare, from facere "to make, do" (see factitious). Related: Deified; deifying.
deign (v.) Look up deign at
c. 1300, from Old French deignier (Modern French daigner), from Latin dignari "to deem worthy or fit" (source of Italian degnare, Spanish deñar), from dignus "worthy" (see dignity). Sense of "take or accept graciously" led to that of "condescend" (1580s). Related: Deigned; deigning.
deinstitutionalization (n.) Look up deinstitutionalization at
1967 (disinstitutionalization is attested from 1955), from de- + institutionalization.
deipnosophist (n.) Look up deipnosophist at
"gourmand," 1650s, from Greek deipnosophistes "one learned in the mysteries of the kitchen," from deipnon "chief meal, dinner" (which is of unknown origin) + sophistes "master of a craft" (see sophist). the word has come down thanks to "Deipnosophistai," 3c. work on gastronomy by Athenaeus.
deism (n.) Look up deism at
1680s (deist is from 1620s), from French déisme, from Latin deus "god" (see Zeus). Until c. 1700, opposed to atheism; later as the opposite of theism (q.v.).
deist (n.) Look up deist at
1620s, from French déiste, from Latin deus (see Zeus). Related: Deistic (1795). Also see deism.
deity (n.) Look up deity at
c. 1300, "divine nature;" late 14c., "a god," from Old French deité, from Late Latin deitatem (nominative deitas) "divine nature," coined by Augustine from Latin deus "god," from PIE *deiwos (see Zeus).
deixis (n.) Look up deixis at
1949, from Greek deixis "reference." Related: Deictic.
deja vu Look up deja vu at
1903, from French déjà vu, literally "already seen." The phenomenon also is known as promnesia. Similar phenomena are déjà entendu "already heard" (of music, etc.), 1965; and déjà lu "already read."
deject (v.) Look up deject at
early 15c., "to throw or cast down," from Old French dejeter (12c.), from Latin deiectus "a throwing down, felling, fall," past participle of deicere "to cast down, destroy; drive out; kill, slay, defeat," from de- "down" + -icere, comb. form of iacere "to throw" (see jet (v.)). Originally literal; the sense of "depress in spirit" is c. 1500.