chiral (adj.)
1894, a hybrid coined by Lord Kelvin from Latinized comb. form of Greek kheir "hand" (from PIE *ghes- "hand;" see chiro-) + -al (1).
chiro-
before verbs chir-, word-forming element meaning "hand," from Latinized form of Greek kheiro-, comb. form of kheir (genitive kheiros) "the hand," from PIE *ghes- "hand" (cognates: Hittite keshshar, Armenian jern "hand").
chirography (n.)
"handwriting," 1650s, from chiro- + -graphy. Chirograph "formal written legal document" is attested from late 13c. in Anglo-French, from Latin chirographum, from Greek kheirographia "written testimony."
chiromancy (n.)
"divination by the hand, palmistry," 1520s, from French chiromancie (14c.), from Medieval Latin chiromantia, from Late Greek kheiromanteia, from kheiro-, comb. form of kheir "hand" (see chiro-) + -mantia (see -mancy). Related: Chiromancer; chiromantic.
Chiron
wisest of the centaurs, from Latin Chiron, from Greek Kheiron, of unknown origin; Klein compares Greek kheirourgos "surgeon."
chiropodist (n.)
1785, from chiro- "hand" + pod-, stem of Greek pous "foot" (see foot (n.)) + -ist. Probably coined by Canadian-born U.S. healer Daniel Palmer (1845-1913); originally they treated both hands and feet. A much-maligned word among classicists, who point out it could mean "having chapped feet" but probably doesn't, and in that case it is an etymological garble and no one can say for sure what it is meant to signify. Related: Chiropody.
chiropractic
coined in American English, 1898 (adj.); 1899 (n.), from chiro- "hand" + praktikos "practical" (see practical), the whole of it loosely meant as "done by hand."
chiropractor (n.)
1904, agent noun in Latin form from chiropractic (q.v.).
chirp (v.)
mid-15c. (implied in chirping), echoic, or else a variant of Middle English chirken "to twitter" (late 14c.), from Old English cearcian "to creak, gnash." Related: Chirped. As a noun, attested from 1802.
chirpy (adj.)
"cheerfully perky," 1825, from chirp + -y (2). The notion is perhaps of birds fluttering and chattering.
chirr (v.)
c.1600, echoic of a grasshopper's trill. Related: Chirred; chirring.
chirrup (v.)
1570s, alternative form chirp (v.).
chirurgeon (n.)
1530s, representing a failed Renaissance attempt to restore Greek spelling to the word that had got into English as surgeon; now, thank the gods, archaic. Related: Chirurgery. Compare French chirurgien.
chisel (n.)
early 14c., from Anglo-French cisel, Old French cisel "chisel," in plural, "scissors, shears" (12c., Modern French ciseau), from Vulgar Latin *cisellum "cutting tool," from Latin caesellum, diminutive of caesus, past participle of caedere "to cut" (see -cide). Related: Chiseled; chiseling.
chisel (v.)
c.1500, "to break with a chisel," from chisel (n.). Slang sense of "to cheat, defraud" is first recorded in 1808 as chizzel; origin and connection to the older word are obscure (compare slang sense of gouge); chiseler in this sense is from 1918. Related: Chiseled; chiseling.
chiseled (adj.)
"having sharp outlines," 1821, figurative past participle adjective from chisel (v.).
chiseler (n.)
1824, "one who works with a chisel," agent noun from chisel (v.). In slang sense of "swindler," attested from 1918.
Chisholm Trail
1866, from Jesse Chisholm (c.1806-1868), halfbreed Cherokee trader and government agent who first plied it. The surname is from a barony in England, probably from Old English cisel "gravel."
chit (n.1)
"note," 1776, short for chitty, from Mahrati (Hindi) chitthi "letter, note," from Sanskrit chitra-s "distinctively marked" (see cheetah).
chit (n.2)
"small child," 1620s, originally "young of a beast" (late 14c.); unrelated to chit (n.1); perhaps a playful deformation of kitten, but the "Middle English Dictionary" compares Old High German kizzin "kid."
chitchat (n.)
also chit-chat, 1710, diminishing reduplicated form of chat. The verb is attested from 1821. Related: Chitchatting.
chitin (n.)
1836, from French chitine, from Greek khiton "frock, tunic," of soldiers, "coat of mail," used metaphorically for "any coat or covering." "Probably an Oriental word" [Liddell & Scott]. Klein compares Hebrew kuttoneth "coat," Aramaic kittana, Arabic kattan "linen."
chiton (n.)
mollusc genus, 1816, from Latinized form of Greek khiton "frock (worn by both sexes), tunic, mail coat" (see chitin). Used in English in literal sense of "ancient Greek tunic" from 1850. The molluscs also are known as "coat-of-mail shells" for their mail-like covering.
chitter (v.)
c.1200, imitative of birds. Related: Chittered; chittering.
chitter-chatter (n.)
1712, reduplicated form of chatter (n.). As a verb from 1804. Related: Chitter-chattering.
chitterlings (n.)
late 13c., cheterlingis "entrails, souse" (early 13c. in surnames), origins obscure, but probably from an unrecorded Old English word having something to do with entrails (related to Old English cwið "womb;" compare German Kutteln "guts, bowels, tripe, chitterlings," Gothic qiþus "womb"). Variants chitlins (1842) and chitlings (1880) both also had a sense of "shreds, tatters."
"While I was in this way rollin' in clover, by picturin' what was to be, they wur tarin' my character all to chitlins up at home." [John S. Robb, "Streaks of Squatter Life," Philadelphia, 1843]
chivalresque (adj.)
1800, from chivalry on analogy of French chevalresque, from chevalier (see chevalier).
chivalric (adj.)
1797, from chivalry + -ic. Pronounced by poets with accent on the middle syllable, and because they are the only ones who need it, that pronunciation might as well be accepted.
chivalrous (adj.)
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.)
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.)
c.1400, from Old North French chive (Old French, Modern French cive, 13c.), from Latin cepa "onion" (see onion).
chivvy (v.)
"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.)
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, military cloak," of unknown origin, + -ia.
Chloe
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 referring to bright materials and gold, and bile or gall (such as Latin helvus "yellowish, bay," Gallo-Latin gilvus "light bay;" Lithuanian geltonas "yellow;" Old Church Slavonic zlutu, Polish żółty, Russian zeltyj "yellow;" Sanskrit harih "yellow, tawny yellow," hiranyam "gold;" Avestan zari "yellow;" Old English geolu, geolwe, Modern English yellow, German gelb "yellow") and "green" (such as Latin galbus "greenish-yellow;" Greek khloros "greenish-yellow color," kholos "bile;" Lithuanian zalias "green," zelvas "greenish;" Old Church Slavonic zelenu, Polish zielony, Russian zelenyj "green;" Old Irish glass, Welsh and Breton glas "green," also "gray, blue").

Buck says the interchange of words for yellow and green is "perhaps because they were applied to vegetation like grass, cereals, etc., which changed from green to yellow." It is possible that this whole group of yellow-green words is related to PIE root *ghlei- "to shine, glitter, glow, be warm" (see gleam (n.)).
chloral (n.)
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.)
"compound of chlorine and another element," 1812, coined by Sir Humphrey Davy (1778-1829) from chlorine + -ide on the analogy of oxide.
chlorinate (v.)
1836 (implied in chlorinated), from chlorine (n.) + -ate (2). Related: Chlorinating.
chlorination (n.)
1854, noun of action from chlorinate (v.).
chlorine (n.)
nonmetallic element, the name coined 1810 by English chemist Sir Humphry Davy (1778-1829) from Latinized form of Greek khloros "pale green" (see Chloe) + chemical suffix -ine (2). Named for its color. Discovered 1774, but known at first as oxymuriatic acid gas, or dephlogisticated marine acid.
chloro-
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 (see Chloe); also compare chlorine.
chlorofluorocarbon (n.)
by 1946, from chloro- + fluorocarbon, from fluor + connective -o- + carbon.
chloroform (n.)
"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" + formique "formic (acid)" (see formic (adj.)). As a verb, from 1848, the year its anaesthetic properties were discovered. Related: Chloroformed.
chlorophyll (n.)
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" (see Chloe) + phyllon "a leaf" (see folio).
chloroplast (n.)
1887, from German chloroplast (1884, E. Strasburger), shortened from chloroplastid (1883, F.W. Schimper); see chloro- + -plast.
choad (n.)
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.)
"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.)
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.)
"tightly, close up against," 1799, back formation from chock-full.
chock-a-block (adj.)
nautical, said of two blocks of tackle run so closely they touch; from chock + block (n.).
chock-full (adj.)
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)).