Online Etymology Dictionary

Q: 16th letter of the classical Roman alphabet, from the Phoenician equivalent of Heb. koph, which was used for the more guttural of the two "k" sounds in Semitic. The letter existed, but was little used and not alphabetized, in Gk.; the stereotypical connection with -u- began in Latin. Anglo-Saxon scribes adopted the habit at first, but later used spellings with cw- or cu-. The qu- pattern returned to Eng. with the Norman Conquest. Scholars use -q- alone to transliterate Sem. koph (e.g. Quran, Qatar, Iraq). In Christian theology, Q has been used since 1901 to signify the hypothetical source of passages shared by Matthew and Luke, but not in Mark; probably it is an abbreviation of Ger. Quelle "source."
Q.E.D.: 1760, abbrev. of L. quod erat demonstrandum "which was to be demonstrated."
q.t.: slang for "quiet," attested from 1884.
qi: "physical life force," 1850, from Chinese qi "air, breath."
qua: "as, in the capacity of," 1647, from L. qua, abl. sing. fem. of qui "who," from PIE *kwo-, stem of relative and interrogative pronouns (cf. O.E. hwa "who," hwæt "what;" Goth. hvas "who;" Gk. posos "how much?").
quaalude: 1965, proprietary name (trademark by Wm. H. Rohrer Inc., Ft. Washington, Pennsylvania, U.S.A.) of methaqualone.
quack (v.): "to make a duck sound," 1617, quelke, of echoic origin (cf. M.Du. quacken, O.C.S. kvakati, L. coaxare "to croak," Gk. koax "the croaking of frogs," Hitt. akuwakuwash "frog"). M.E. on the quakke (14c.) meant "hoarse, croaking."
quack (n.): "medical charlatan," 1638, short for quacksalver (1579), from Du. kwaksalver, lit. "hawker of salve," from M.Du. quacken "to brag, boast," lit. "to croak" (see quack (v.)) + zalf "salve." Cf. Ger. Quacksalber, Dan. kvaksalver, Swed. kvacksalvare.
quadrangle: c.1430, from O.Fr. quadrangle (13c.), from L.L. quadrangulum "four-sided figure," prop. neut. of L. adj. quadrangulus "having four quarters," from L. quattuor "four" (see four) + angulus "angle." The shortened form quad for "quadrangle of a college," is first recorded 1820 in Oxford slang.
quadrant: late 14c., "a quarter of a day, six hours," from L. quadrantem (nom. quadrans) "fourth part," prop. prp. of quadrare "to make square," from quadrus "a square," from quattuor "four" (see four). Sense of "measuring instrument" is first recorded c.1400, so called because it forms a quarter circle.
quadraphonic: 1969, irregular formation from quadri- "four" + phonic, from Gk. phone "sound, voice" (see fame). The goal was to reproduce front-to-back sound distribution in addition to side-to-side stereo.
quadratic: 1650s, "square," from quadrate (late 14c.), from L. quadratus "square," pp. of quadrare "to square," related to quattuor "four" (see four). Quadratic equations (1660s) so called because they involve the square of x.
quadrilateral (n.): 1650, from L. quadrilaterus, from quadri- "four" + latus (gen. lateris) "side" (see oblate (n.)).
quadrille: 1773, "lively square dance for four couples," from Fr. quadrille, originally one of four groups of horsemen in a tournament (a sense attested in Eng. from 1738), from Sp. cuadrilla, dim. of cuadro "four-sided battle square," from L. quadrum "a square," related to quattuor "four" (see four). The craze for the dance hit England in 1816, and it underwent a vigorous revival late 19c. among the middle classes. Earlier a popular card game for four hands (1726).
"Quadrille began to take the place of ombre as the fashionable card game about 1726, and was in turn superseded by whist." [OED]
quadrillion: 1674, from Fr. quadrillion (16c.) from quadri- "four" + (m)illion. Cf. billion. In Great Britain, the fourth power of a million (1 followed by 24 zeroes); in the U.S., the fifth power of a thousand (1 followed by 15 zeroes).
quadriplegic (adj.): 1921, a medical hybrid coined from L. prefix quadri- "four" + -plegic, as in paraplegic, ult. from Gk. plege "stroke," from root of plessein "to strike." A correct, all-Gk. form would be *tessaraplegic. The noun is first attested 1958, from the adj.
quadroon: 1707, "offspring of a white and a mulatto," from Sp. cuarteron (used chiefly of the offspring of a European and a mestizo), from cuarto "fourth," from L. quartus (see quart), so called because he or she has one quarter African blood. Alt. by infl. of words in quadr-.
quadruped: 1620 (implied in quadrupedal), from Fr. quadrupède, from M.Fr., from L. quadrupes (gen. quadrupedis) "four-footed, a four-footed animal," from quadri- "four" + pes "foot." The adj. is attested from 1741.
quadruple (v.): late 14c., from L. quadruplare "make fourfold," from quadruplus (n.) "quadruple," from quadri- "four" + -plus "fold." Quadruplets "four children in one birth" is first recorded 1787. The abbreviation of it to quad is first attested 1851.
quaff (v.): 1520 (implied in quaffer), perhaps onomatopoeic, or perhaps from Low Ger. quassen "to overindulge (in food and drink)," with -ss- misread as -ff-. The noun is from 1579.
quagga: 1785, from Afrikaans (1710), from the name for the beast in a native language, perhaps Hottentot quacha, probably of imitative origin. In modern Xhosa, the form is iqwara, with a clicking -q-. The last one died in an Amsterdam zoo in 1883.
quagmire: 1579, from obsolete quag "bog, marsh" + mire. Quag is a variant of M.E. quabbe "a marsh, bog," from O.E. *cwabba "shake, tremble" (like something soft and flabby). Extended sense of "difficult situation, inextricable position" is first recorded 1775.
quahog: 1753, from an Algonquian language, perhaps Narragansett poquauhock or Pequot p'quaghhaug "hard clam."
quai: 1870, from Fr. quai (see quay). Often short for Quai D'Orsay, street on the south bank of the Seine in Paris, site of the Fr. Ministry of Foreign Affairs and sometimes used metonymically for it (1922).
quail (n.): c.1300, quayle, from O.Fr. quaille, perhaps via M.L. quaccula (cf. Prov. calha, It. quaglia, O.Sp. coalla), from a Gmc. source (cf. O.H.G. quahtala "quail," Ger. Wachtel), imitative of the bird's cry. Or the Eng. word may be directly from Gmc. Slang meaning "young attractive woman" first recorded 1859.
quail (v.): "to lose heart, to shrink," mid-15c., of unknown origin, perhaps from M.Du. quelen "to suffer, be ill," from P.Gmc. *kwel- "to die" (see quell). Or from obsolete quail "to curdle" (late 14c.), from O.Fr. coailler, from L. coagulare (see coagulate). Sense of "cower" is attested from 1550s. Common 1520-1650, then rare until 19c.; apparently revived by Scott.
quaint: early 13c., "cunning, proud, ingenious," from O.Fr. cointe "pretty, clever, knowing," from L. cognitus "known," pp. of cognoscere "get or come to know well" (see cognizance). Sense of "old-fashioned but charming" is first attested 1795, and could describe the word itself, which had become rare after c.1700 (though it soon recovered popularity in this secondary sense). Chaucer used quaint and queynte as spellings of cunt in "Canterbury Tales" (c.1386), and Andrew Marvell may be punning on it similarly in "To His Coy Mistress" (1650).
quake (v.): O.E. cwacian "quake, tremble, chatter (of teeth)," related to cweccan "to shake, swing, move, vibrate," of unknown origin with no certain cognates outside Eng. Perhaps somehow imitative. The noun is attested from c.1300, but was rare except in combinations.
Quaker: 1651, said to have been applied to them in 1650 by Justice Bennett at Derby, from George Fox's admonition to his followers to "tremble at the Word of the Lord;" but the word was used earlier of foreign sects given to fits of shaking during religious fervor, and that is likely the source here. Either way, it was never an official name of the Religious Society of Friends. Quaker gun (1809, Amer.Eng.) was a log painted black and propped up to look from a distance like a cannon.
qualify: 1465, "to invest with a quality," from M.L. qualificare "attribute a quality to," from L. qualis "of what sort" + facere "to make" (see factitious). Sense of "be fit for a job" first appeared 1588. Qualification in the sense of "limitation, restriction" is from 1543.
qualitative: c.1600, from L.L. qualitativus, from L. qualitas (see quality).
quality: late 13c., from O.Fr. qualite (12c., Fr. qualité), from L. qualitatem (nom. qualitas; said to have been coined by Cicero to translate Gk. poiotes), from qualis "of what sort," from PIE pronomial base *kwo- (see qua). Noun phrase quality time first recorded 1977. Quality of life is from 1943. Quality control first attested 1935.
qualm: O.E. cwealm (W.Saxon) "death, disaster, plague," utcualm (Anglian) "utter destruction," related to cwellan "to kill," cwelan "to die" (see quell). Sense softened to "feeling of faintness" 1530; meaning "uneasiness, doubt" is from 1553; that of "scruple of conscience" is 1649. A direct connection between the O.E. and modern senses is wanting, but it is nonetheless plausible, via the notion of "fit of sickness." The other suggested etymology, less satisfying, is from Du. kwalm "steam, vapor, mist," which also may be ult. from the same Gmc. root as quell.
qualms: see qualm.
quandary: 1579, "state of perplexity," of unknown origin, perhaps a quasi-Latinism based on L. quando "when."
quantify: c.1840, as a term in logic, from M.L. quantificare, from L. quantus "how much" + facere "to make" (see factitious). Lit. sense of "determine the quantity of, measure" is from 1878.
quantitative: 1580s, from M.L. quantitativus, from L. quantitas (see quantity).
quantity: early 14c., from O.Fr. quantite (Fr. quantité), from L. quantitatem (nom. quantitas, coined as a loan-translation of Gk. posotes) "relative greatness or extent," from quantus "how much," from quam "how, how much."
quantum: 1619, "one's share or portion," from L. quantum "how much," neut. sing. of quantus "how great" (see quantity). Introduced in physics by Max Planck, 1900; reinforced by Einstein, 1905. Quantum theory is from 1912; quantum mechanics, 1922; quantum jump is first recorded 1955; quantum leap, 1970.
quarantine: 1520s, "period of 40 days in which a widow has the right to remain in her dead husband's house." Earlier (15c.), "desert in which Christ fasted for 40 days," from L. quadraginta "forty," related to quattuor "four" (see four). Sense of "period a ship suspected of carrying disease is kept in isolation" is 1660s, from It. quarantina giorni, lit. "space of forty days," from quaranta "forty," from L. quadraginta. So called from the Venetian custom of keeping ships from plague-stricken countries waiting off its port for 40 days (first enforced at Ragusa late 14c.). The extended sense of "any period of isolation" is from 1680.
quark: 1964, applied by U.S. physicist Murray Gell-Mann (b.1929), who said he took it from a nonsense word in James Joyce's "Finnegans Wake" (1939).
quarrel (1): "angry dispute," mid-14c., "ground for complaint," from O.Fr. querele, from L. querella "complaint," from queri "to complain, lament." Replaced O.E. sacan. Sense of "contention between persons" is from 1570s. The verb is attested from late 14c. in the sense "to raise an objection;" 1520s with the meaning "to contend violently, to fall out."
quarrel (2): "square-headed bolt for a crossbow," early 13c., from O.Fr. quarel, from V.L. *quadrellus, dim. of L.L. quadrus (adj.) "square," related to quattuor "four" (see four). Archaic sense of "square or diamond-shaped plane of glass" first recorded mid-15c.
quarrelsome: 1590s, from quarrel (1) + -some.
quarry (1): "what is hunted," c.1320, quirre "entrails of deer placed on the hide and given to dogs of the chase as a reward," from Anglo-Fr. quirreie, from O.Fr. cuiriee, altered (by influence of O.Fr. cuir "skin," from L. corium "hide"), from O.Fr. corée "viscera, entrails," from V.L. *corata "entrails," from L. cor "heart." Sense of "anything chased in hunt" is first recorded 1615; earlier "bird targeted by a hawk or other raptor" (1486).
quarry (2): "where rocks are excavated," c.1400, from M.L. quarreria (1266), lit. "place where stones are squared," from L. quadrare "to square" (see quadrant). The verb is attested from 1774.
quart: early 14c., "one-fourth of a gallon," from O.Fr. quarte "a fourth part" (13c.), from L. quarta (pars), from fem. of quartus "fourth," related to quattuor "four," from PIE base *kewtwor- (see four).
quarter (n.): c.1300, "one-fourth of anything," from O.Fr. quartier (12c.), from L. quartarius "fourth part," from quartus "fourth" (see quart). Earliest sense is "parts of the body as dismembered during execution" (c.1300). Used of the moon from c.1400 and the hour from 1599. The coin is peculiar to U.S., first recorded 1783. Meaning "region, locality" is from c.1300. Meaning "portion of a town" (identified by the class or race of people who live there) is first attested 1526. The verb meaning "to cut in quarters" is recorded from c.1430. Quarter days (1480), when rents were paid and contracts and leases began or expired, were, in England, Lady day (March 25), Midsummer day (June 24), Michaelmas day (Sept. 29), and Christmas day (Dec. 25); in Scotland, keeping closer to the pagan Celtic calendar, they were Candlemas (Feb. 2), Whitsunday (May 15), Lammas (Aug. 1), and Martinmas (Nov. 11). Quarter horse, bred strong for racing on quarter-mile tracks, first recorded 1834; quarterback (n.) in U.S. football is from 1879; the verb is first attested 1945. Monday morning quarterback originally was pro football player slang for sportswriters, attested from 1932.
quarters: "military dwelling place," 1591, from quarter (n.) in sense of "portion of a town." The military sense is in quartermaster (1442) and may be behind the phrase give (no) quarter (1611), on the notion of "to provide a prisoner with shelter." The verb quarter "to put up soldiers" is recorded from 1594.
quarterstaff: c.1550, stout pole, six to eight feet long, tipped with iron, formerly a weapon used by the Eng. peasantry. The exact sense of quarter is uncertain here; it may be from a tree of a certain size cut into quarters.