chivalrous (adj.) Look up chivalrous at Dictionary.com
mid-14c., from Old French chevaleros "knightly, noble, chivalrous," from chevalier (see chevalier; also compare chivalry). According to OED, obsolete in English and French from mid-16c. Not revived in French, but brought back in English late 18c. by romantic writers fond of medieval settings.
chivalry (n.) Look up chivalry at Dictionary.com
c. 1300, "body or host of knights; knighthood in the feudal social system; bravery in war, warfare as an art," from Old French chevalerie "knighthood, chivalry, nobility, cavalry, art of war," from chevaler "knight," from Medieval Latin caballarius "horseman," from Latin caballus "nag, pack-horse" (see cavalier). From late 14c. as "the nobility as one of the estates of the realm," also as the word for an ethical code emphasizing honor, valor, generosity and courtly manners. Modern use for "social and moral code of medieval feudalism" probably is an 18c. historical revival.
chive (n.) Look up chive at Dictionary.com
c. 1400, from Old North French chive (Old French, Modern French cive, 13c.), from Latin cepa "onion" (see onion).
chivvy (v.) Look up chivvy at Dictionary.com
"harass," 1918, from alternative form of chevy (1830) "to chase," from a noun chevy (1824, also used as a hunting cry, c. 1785), from chevy chase "a running pursuit," probably from the "Ballad of Chevy Chase," popular song from 15c. describing a hunting party on the borderland that turned into a battle between the English and the Scots (the incident probably late 14c.). The place is probably originally Cheviot Chase.
The old song of Chevy-Chase is the favourite ballad of the common people of England, and Ben Jonson used to say, he had rather have been the author of it than of all his works. [Addison, "spectator" No. 70, May 21, 1711]
chlamydia (n.) Look up chlamydia at Dictionary.com
type of genital infection, 1984, from the name of the bacteria that causes it (1945), which is formed from Latinized comb. form of Greek khlamys (genitive khlamydos) "short mantle, upper garment for men, military cloak," which is of unknown origin, + abstract noun ending -ia. Said to be so called due to its ability to "cloak" the nuclei of infected cells.
Chloe Look up Chloe at Dictionary.com
fem. proper name, Latin, from Greek Khloe, literally "young green shoot;" related to khloros "greenish-yellow," from PIE *ghlo- variant of root *ghel- (2) "to shine," with derivatives denoting "green" and "yellow."
chloral (n.) Look up chloral at Dictionary.com
colorless liquid formed by the action of chlorine on alcohol, apparently coined by German chemist Justus von Liebig in 1833 from elements from chlorine + alcohol. Later chiefly in chloral hydrate (1874).
chloride (n.) Look up chloride at Dictionary.com
"compound of chlorine and another element," 1812, coined by Sir Humphrey Davy (1778-1829) from chlorine + -ide on the analogy of oxide.
chlorinate (v.) Look up chlorinate at Dictionary.com
1836 (implied in chlorinated), from chlorine (n.) + -ate (2). Related: Chlorinating.
chlorination (n.) Look up chlorination at Dictionary.com
1854, noun of action from chlorinate (v.).
chlorine (n.) Look up chlorine at Dictionary.com
nonmetallic element, the name coined 1810 by English chemist Sir Humphry Davy (1778-1829) from Latinized form of Greek khloros "pale green" (from PIE root *ghel- (2) "to shine," with derivatives denoting "green" and "yellow") + chemical suffix -ine (2). Named for its color. Discovered 1774, but known at first as oxymuriatic acid gas, or dephlogisticated marine acid.
chloro- Look up chloro- at Dictionary.com
before vowels chlor-, word-forming element used in chemistry, usually indicating the presence of chlorine in a compound, but sometimes "green," from Latinized comb. form of Greek khloros "greenish-yellow" (from PIE root *ghel- (2) "to shine," with derivatives denoting "green" and "yellow"); also compare chlorine.
chlorofluorocarbon (n.) Look up chlorofluorocarbon at Dictionary.com
by 1946, from chloro- + fluorocarbon.
chloroform (n.) Look up chloroform at Dictionary.com
"trichloromethane," volatile liquid used as an anaesthetic, 1835, from French chloroforme, a hybrid coined 1834 by French chemist Jean-Baptiste Dumas (1800-1884) from chlor-, comb. form meaning "chlorine" (see chlorine) + formique "formic (acid)" (see formic (adj.)). As a verb, from 1848, the year its anaesthetic properties were discovered. Related: Chloroformed.
chlorophyll (n.) Look up chlorophyll at Dictionary.com
green-colored stuff in plants, 1819, from French chlorophyle (1818), coined by French chemists Pierre-Joseph Pelletier (1788-1842) and Joseph Bienaimé Caventou (1795-1877) from Greek khloros "pale green, greenish-yellow" (from PIE root *ghel- (2) "to shine," with derivatives denoting "green" and "yellow") + phyllon "a leaf" (from suffixed form of PIE root *bhel- (3) "to thrive, bloom").
chloroplast (n.) Look up chloroplast at Dictionary.com
1887, from German chloroplast (1884, E. Strasburger), shortened from chloroplastid (1883, F.W. Schimper); see chloro- + -plast.
choad (n.) Look up choad at Dictionary.com
also chode, "penis," c. 1968, U.S. teen slang, of unknown origin. Guesses include supposed Navajo chodis "penis" ["Cassell's Dictionary of Slang" 2005], or a supposed Hindi, Bengali or Gujarati vernacular word for "copulate" ["New Hacker's Dictionary," 1996].
choate (adj.) Look up choate at Dictionary.com
"finished, complete," mistaken back-formation from inchoate (q.v.) as though that word contained in- "not." First attested 1878 in letter from Oliver Wendell Holmes lamenting barbarisms in legal case writing (he said he found choate in a California report).
chock (n.) Look up chock at Dictionary.com
1670s, "lumpy piece of wood," possibly from Old North French choque "a block" (Old French çoche "log," 12c.; Modern French souche "stump, stock, block"), from Gaulish *tsukka "a tree trunk, stump."
chock (adv.) Look up chock at Dictionary.com
"tightly, close up against," 1799, back formation from chock-full.
chock-a-block (adj.) Look up chock-a-block at Dictionary.com
nautical, said of two blocks of tackle run so closely they touch; from chock + block (n.1) in the nautical sense "a pulley together with its framework."
chock-full (adj.) Look up chock-full at Dictionary.com
c. 1400, chokkeful "crammed full," possibly from choke "cheek" (see cheek (n.)). Or it may be from Old French choquier "collide, crash, hit" (13c., Modern French choquer), which is probably from Germanic (compare Middle Dutch schokken; see shock (n.1)).
chocolate (n.) Look up chocolate at Dictionary.com
c. 1600, from Nahuatl (Aztecan) xocolatl, possibly from xocolia "to make bitter" + atl "water." Brought to Spain by 1520, from thence to the rest of Europe. Originally a drink; as a paste or cake made of ground, roasted, sweetened cacao seeds, 1640s.
To a Coffee-house, to drink jocolatte, very good [Pepys, "Diary," Nov. 24, 1664].
As a color from 1776. Chocolate chip is from 1940; chocolatier is attested from 1888.
chocolatey (adj.) Look up chocolatey at Dictionary.com
1922, chocolate-y, from chocolate + -y (2). Related: Choclatiness.
Choctaw Look up Choctaw at Dictionary.com
1722, from Choctaw (Muskogean) Chahta, of uncertain meaning, but also said to be from Spanish chato "flattened," for the tribe's custom of flattening the heads of male infants. As a figure skating step, first recorded 1892. Sometimes used in 19c. American English as typical of a difficult or incomprehensible language (compare Greek in this sense from c. 1600).
choice (adj.) Look up choice at Dictionary.com
"worthy to be chosen, distinguished, excellent," mid-14c., from choice (n.). Related: Choiceness.
choice (n.) Look up choice at Dictionary.com
mid-14c., "that which is choice," from choice (adj.) blended with earlier chois (n.) "action of selecting" (c. 1300); "power of choosing" (early 14c.), "someone or something chosen" (late 14c.), from Old French chois "one's choice; fact of having a choice" (12c., Modern French choix), from verb choisir "to choose, distinguish, discern; recognize, perceive, see," from Frankish or some other Germanic source related to Old English ceosan "to choose, taste, try" (from PIE root *geus- "to taste; to choose").

Late Old English chis "fastidious, choosy," from or related to ceosan, probably also contributed to the development of choice. Replaced Old English cyre "choice, free will," from the same base, probably because the imported word was closer to choose [see note in OED].
choir (n.) Look up choir at Dictionary.com
c. 1300, queor "part of the church where the choir sings," from Old French cuer, quer "choir of a church (architectural); chorus of singers" (13c., Modern French choeur), from Latin chorus "choir" (see chorus). Meaning "band of singers" is c. 1400, quyre. Re-spelled mid-17c. on Latin model.
choir-boy (n.) Look up choir-boy at Dictionary.com
also choir boy, 1769, from choir + boy. As a type of innocence, by 1885.
chokage (n.) Look up chokage at Dictionary.com
1847, from choke (n.) + -age.
choke (v.) Look up choke at Dictionary.com
c. 1300, transitive, "to strangle;" late 14c., "to make to suffocate," of persons as well as swallowed objects, a shortening of acheken (c. 1200), from Old English aceocian "to choke, suffocate" (with intensive a-), probably from root of ceoke "jaw, cheek" (see cheek (n.)).

Intransitive sense from c. 1400. Meaning "gasp for breath" is from early 15c. Figurative use from c. 1400, in early use often with reference to weeds stifling the growth of useful plants (a Biblical image). Meaning "to fail in the clutch" is attested by 1976, American English. Related: Choked; choking. Choke-cherry (1785) supposedly so called for its astringent qualities. Johnson also has choke-pear "Any aspersion or sarcasm, by which another person is put to silence." Choked up "overcome with emotion and unable to speak" is attested by 1896. The baseball batting sense is by 1907.
choke (n.) Look up choke at Dictionary.com
1560s, "quinsy," from choke (v.). Meaning "action of choking" is from 1839. Meaning "valve which controls air to a carburetor" first recorded 1926.
choke-hold (n.) Look up choke-hold at Dictionary.com
1962, from choke + hold (n.).
choker (n.) Look up choker at Dictionary.com
1550s, "one who chokes," agent noun from choke (v.). From 1848 as "large neckerchief;" as a kind of necklace, 1928.
cholecyst (n.) Look up cholecyst at Dictionary.com
"gall bladder," 1846, from medical Latin cholecystis, incorrectly formed from Greek khole "gall" (from PIE root *ghel- (2) "to shine," with derivatives denoting "green, yellow," and thus "bile, gall") + kystis "bladder, cyst" (see cyst). Related: Cholecystectomy.
cholecystitis (n.) Look up cholecystitis at Dictionary.com
1846, from cholecyst + -itis "inflammation."
choler (n.) Look up choler at Dictionary.com
late 14c., "bile," as one of the humors, supposed to cause irascibility or temper, from Old French colere "bile, anger," from Late Latin cholera "bile" (see cholera).
cholera (n.) Look up cholera at Dictionary.com
late 14c., "bile, melancholy" (originally the same as choler), from Middle French cholera or directly from Late Latin cholera, from Greek kholera "a type of disease characterized by diarrhea, supposedly caused by bile" (Celsus), from khole "gall, bile," so called for its color, related to khloazein "to be green," khloros "pale green, greenish-yellow," from PIE root *ghel- (2) "to shine," with derivatives denoting "green, yellow," and thus "bile, gall." But another sense of khole was "drainpipe, gutter."

Revived 1560s in classical sense as a name for a severe digestive disorder (rarely fatal to adults); and 1704 (especially as cholera morbus), for a highly lethal disease endemic in India, periodically breaking out in global epidemics, especially that reaching Britain and America in the early 1830s.
choleraic (adj.) Look up choleraic at Dictionary.com
"pertaining to cholera," 1832, from cholera + -ic.
choleric (adj.) Look up choleric at Dictionary.com
mid-14c., colrik, "bilious of temperament or complexion," from Old French colerique, from Late Latin cholericus, from Greek kholerikos, from Greek kholera "a type of disease characterized by diarrhea, supposedly caused by bile," from khole "gall, bile," so called for its color, related to khloazein "to be green," khloros "pale green, greenish-yellow," from PIE root *ghel- (2) "to shine," with derivatives denoting "green, yellow," and thus "bile, gall." Meaning "easily angered, hot-tempered" is from 1580s (from the supposed effect of excess choler); that of "pertaining to cholera" is from 1834.
cholesterol (n.) Look up cholesterol at Dictionary.com
white, solid substance present in body tissues, 1894, earlier cholesterin, from French cholestrine (Chevreul, 1827), from Greek khole "bile" (from PIE root *ghel- (2) "to shine," with derivatives denoting "green, yellow," and thus "bile, gall") + steros "solid, stiff" (from PIE root *ster- (1) "stiff"). So called because originally found in gallstones (Conradi, 1775). The name was changed to the modern form (with chemical suffix -ol, denoting an alcohol) after the compound was discovered to be a secondary alcohol.
cholinergic (adj.) Look up cholinergic at Dictionary.com
1934, from choline (coined in German, 1862, from Greek khole "bile;" see cholera) + Greek ergon "work" (from PIE root *werg- "to do") + -ic.
Cholo Look up Cholo at Dictionary.com
"Indian or mixed-race person of Latin America" (fem. Chola), 1851, from American Spanish (c. 1600), said to be from Nahuatl (Aztecan) xolotl "dog, mutt." Proposed derivation from Mexican city of Cholula seems too late, if this is the same word. In U.S., used of lower-class Mexican immigrants, but by 1970s the word began to be embraced in Latino gang slang in a positive sense.
chomp (v.) Look up chomp at Dictionary.com
1640s, dialectal and American English variant of champ (v.). Related: Chomped; chomping.
chondro- Look up chondro- at Dictionary.com
word-forming element meaning "cartilage," from Latinized form of Greek khondros "cartilage" (of the breastbone), also "grain, grain of salt, seed, barley-grain," of uncertain origin. This is sometimes said to be from the PIE root meaning "to grind" which is the source of English grind (v.), but there are serious phonological objections and the word might be non-Indo-European [Beekes, "Etymological Dictionary of Greek"]. The body material so called for its gristly nature.
choo-choo (n.) Look up choo-choo at Dictionary.com
Child's name for "steam-engine locomotive," 1895, echoic (choo-choo cars is attested from 1891).
choose (v.) Look up choose at Dictionary.com
Old English ceosan "choose, seek out, select; decide, test, taste, try; accept, approve" (class II strong verb; past tense ceas, past participle coren), from Proto-Germanic *keus- (source also of Old Frisian kiasa, Old Saxon kiosan, Dutch kiezen, Old High German kiosan, German kiesen, Old Norse kjosa, Gothic kiusan "choose," Gothic kausjan "to taste, test"), from PIE root *geus- "to taste; to choose." Only remotely related to choice. Variant spelling chuse is Middle English, very frequent 16c.-18c. The irregular past participle leveled out to chosen by 1200.
choosy (adj.) Look up choosy at Dictionary.com
1862, American English, from choose + -y (2). Also sometimes choosey. Related: Choosiness.
chop (v.1) Look up chop at Dictionary.com
"to cut with a quick blow," mid-14c., of uncertain origin, perhaps from Old North French choper (Old French coper "to cut, cut off," 12c., Modern French couper), from Vulgar Latin *cuppare "to behead," from a root meaning "head," but influenced in Old French by couper "to strike." Related: Chopped; chopping.
chop (v.2) Look up chop at Dictionary.com
"shift quickly," 1530s, earlier "to bargain" (early 15c.), ultimately from Old English ceapian "to bargain" (see cheap); here with a sense of "changing back and forth," probably from common expressions such as to chop and change "barter." To chop logic is recorded from 1570s. Related: Chopped; chopping.