Online Etymology Dictionary

cautionary (adj.): "conveying a warning," 1590s, from caution (n.) + -ary.
cautious (adj.): 1640s, from caution + -ous. The Latin word for this was cautus "careful, heedful." Related: Cautiously; cautiousness.
cavalcade (n.): 1590s, via Middle French cavalcade (15c.), from Italian cavalcata, from cavalcare "to ride on horseback," from Vulgar Latin *caballicare (also source of Spanish cabalgada, Portuguese cavalgata), from Latin caballus (see cavalier). Literally, "a procession on horseback;" in 20c. -cade came to be regarded as a suffix and taken to form motorcade (1913), etc.
cavalier (n.): 1580s, from Italian cavalliere "mounted soldier, knight; gentleman serving as a lady's escort," from Late Latin caballarius "horseman," from Vulgar Latin caballus, the common Vulgar Latin word for "horse" (and source of Italian cavallo, French cheval, Spanish caballo, Irish capall, Welsh ceffyl), displacing Latin equus (see equine).

Sense advanced in 17c. to "knight," then "courtly gentleman" (but also, pejoratively, "swaggerer"), which led to the adjectival senses, especially "disdainful" (1650s). Meaning "Royalist adherent of Charles I" is from 1641. Meaning "one who devotes himself solely to attendance on a lady" is from 1817, roughly translating Italian cavaliere-servente. In classical Latin caballus was "work horse, pack horse," sometimes, disdainfully, "hack, nag." "Not a native Lat. word (as the second -a- would show), though the source of the borrowing is uncertain" [Tucker]. Perhaps from some Balkan or Anatolian language, and meaning, originally, "gelding." The same source is thought to have yielded Old Church Slavonic kobyla.
cavalier (adj.): "disdainful," 1650s, from cavalier (n.). Earlier it meant "gallant" (1640s). Related: Cavalierly.
cavalry (n.): 1540s, from Middle French cavalerie (16c.), from Italian cavalleria "mounted militia," from cavaliere (see cavalier (n.)). An Old English word for it was horshere.
cave (n.): early 13c., from Old French cave "a cave, vault, cellar" (12c.), from Latin cavea "hollow" (place), noun use of neuter plural of adjective cavus "hollow," from PIE root *keue- "a swelling, arch, cavity" (see cumulus). Replaced Old English eorðscrafu. First record of cave man is 1865.
cave (v.): early 15c., caven, "to hollow something out," from cave (n.). Modern sense "to collapse in or down" is 1707, American English, presumably from East Anglian dialectal calve "collapse, fall in," perhaps from Flemish; subsequently influenced by cave (n.). Transitive sense by 1762. Related: Caved; caving. Figurative sense of "yield to pressure" is from 1837.
caveat (n.): 1540s, from Latin, literally "let him beware," 3rd person singular present subjunctive of cavere "to beware, take heed, watch, guard against," from PIE root *skeue- "to pay attention, perceive" (source also of Sanskrit kavih "wise, sage, seer, poet;" Lithuanian kavoti "tend, safeguard;" Armenian cucanem "I show;" Latin cautio "wariness;" Greek koein "to mark, perceive, hear," kydos "glory, fame," literally "that which is heard of;" Old Church Slavonic chujo "to feel, perceive, hear," cudo "wonder," literally "that which is heard of;" Czech (z)koumati "to perceive, be aware of;" Serbian chuvati "watch, heed;" Old English sceawian "to look at" (source of show (v.)); Middle Dutch schoon "beautiful, bright," properly "showy;" Gothic hausjan "hear").
caveat emptor: Latin, literally "let the buyer beware;" see caveat and second element of exempt (adj.).
cavern (n.): late 14c., from Old French caverne (12c.) "cave, vault, cellar," from Late Latin caverna "cave," from Latin cavus "hollow" (see cave (n.)). In Old English such a land feature might be called an eorðscræf.
cavernous (adj.): c. 1400, "full of caverns," from Latin cavernosus "full of cavities" (source also of Italian cavernoso, French caverneux), from caverna (see cavern). Meaning "hollow" is recorded from 1830.
caviar (n.): also caviare, 1550s, from French caviar (16c.), from Italian caviaro (modern caviale) or Turkish khaviar, from Persian khaviyar, from khaya "egg" (from Middle Persian khayak "egg," from Old Iranian *qvyaka-, diminutive of *avya-, from PIE *owyo-/*oyyo- "egg" see egg (n.)) + dar "bearing."
cavil (v.): 1540s, from Middle French caviller "to mock, jest," from Latin cavillari "to jeer, mock; satirize, argue scoffingly" (also source of Italian cavillare, Spanish cavilar), from cavilla "jest, jeering," related to calumnia (see calumny).
cavitate (v.): 1892 (implied in cavitated), back-formation from cavitation. Related: Cavitating.
cavitation (n.): "formation of bubbles in fluid," 1895, from cavity + -ation. Earlier as a medical term (1868).
cavity (n.): 1540s, from Middle French cavité (13c.), from Late Latin cavitatem (nominative cavitas) "hollowness," from Latin cavus "hollow" (see cave (n.)).
cavort (v.): 1793, cauvaut, American English, of uncertain origin, sometimes said to be an alteration of curvet "a leap by a horse," from French and related to curve (v.). Or perhaps from ca- colloquial intensive prefix + vault "to jump, leap." Modern form attested by 1829. Related: Cavorted; cavorting.
caw (v.): "make a sound like a crow, raven, etc.," 1580s, imitative. Related: Cawed; cawing.
caw (n.): 1660s, from caw (v.).
cay (n.): "low island," 1707, from Spanish cayo; see key (n.2).
cayenne (n.): "pungent dried pepper," 1756, from Tupi (Brazil) kyynha "capsicum," mistakenly associated with town of Cayenne in French Guyana. The town name is the French form of Guyana.
cayuse (n.): "horse, Indian pony," 1841, American English, said to be a Chinook (native Pacific Northwest) word; also the name of an Indian group and language (1825), of unknown origin.
CB: 1959, abbreviation of citizens' band (radio).
cc: 1936 as abbreviation of carbon copy in business correspondence.
CD: 1979 as an abbreviation of compact disc as a system of information storage.
CD-ROM: 1983, in computer jargon; also cd-rom; from compact disc read-only memory.
CDC: abbreviation of Centers for Disease Control, renamed 1970 from earlier U.S. federal health lab, originally Communicable Diseases Center (1946). Since 1992, full name is Centers for Disease Control and Prevention, but the usual initialism (acronym) remains CDC.
cease (v.): c. 1300, cesen, from Old French cesser "to come to an end, stop, cease; give up, desist," from Latin cessare "to cease, go slow, give over, leave off, be idle," frequentative of cedere (past participle cessus) "go away, withdraw, yield" (see cede). Related: Ceased; ceasing. Old English in this sense had geswican, blinnan.
cease (n.): "cessation, stopping," c. 1300, from cease (n.) or else from Old French cesse "cease, cessation," from cesser.
cease-fire (n.): also ceasefire, "a cessation of shooting," 1916, from verbal phrase cease fire, 1847 as a military command (formerly also signaled by bugles), from cease (v.) + fire (n.) in the gunnery sense. Generally two words until after mid-20c.
ceaseless (adj.): 1580s, from cease (n.) + -less. Related: Ceaselessly; ceaselessness.
Cecil: masc. proper name, from Latin Caecilius (fem. Caecilia), name of a Roman gens, from caecus "blind."
Cecilia: fem. proper name, fem. of Cecil (q.v.).
cecum (n.): variant of caecum.
cedar (n.): Old English ceder, blended in Middle English with Old French cedre, both from Latin cedrus, from Greek kedros "cedar, juniper," origin uncertain. Cedar oil was used by the Egyptians in embalming as a preservative against decay and the word for it was used figuratively for "immortality" by the Romans. Cedar chest attested from 1722. Related: Cedrine.
cede (v.): 1630s, from French céder or directly from Latin cedere "to yield, give place; to give up some right or property," originally "to go from, proceed, leave," from Proto-Italic *kesd-o- "to go away, avoid," from PIE root *sed- (2) "to go, yield" (source also of Sanskrit sedhati "to drive; chase away;" Avestan apa-had- "turn aside, step aside;" Greek hodos "way," hodites "wanderer, wayfarer;" Old Church Slavonic chodu "a walking, going," choditi "to go"). Related: Ceded; ceding. The sense evolution in Latin is via the notion of "to go away, withdraw, give ground."
cedilla (n.): c. 1600, from Spanish cedilla, zedilla, literally "little z," from a Latin-like diminutive of Greek zeta "the letter 'z'." The mark (formerly also used in Spanish) was derived from that letter and indicates a "soft" sound in letters in positions where normally they have a "hard" sound. See zed.
Cedric: masc. proper name, modern, apparently introduced by Sir Walter Scott (Cedric the Saxon is a character in "Ivanhoe"); apparently a mistake for Old English name Cerdic.
cee (n.): "name of the letter C," 1540s.
ceilidh (n.): 1875, from Irish céilidhe, from Old Irish céle "companion," from PIE *kei-liyo-, from root *kei- "beloved, dear," primarily "to lie; bed, couch" (see cemetery).
ceiling (n.): mid-14c., celynge, "act of paneling a room," noun formed (with -ing) from Middle English verb ceil "put a cover or ceiling over," later "cover (walls) with wainscoting, panels, etc." (early 15c.); probably from Middle French celer "to conceal," also "cover with paneling" (12c.), from Latin celare (see cell). Probably influenced by Latin caelum "heaven, sky" (see celestial).

Extended to the paneling itself from late 14c. The meaning "top surface of a room" is attested by 1530s. Figurative sense "upper limit" is from 1934. Colloquial figurative phrase hit the ceiling "lose one's temper, get explosively angry" attested by 1908; earlier it meant "to fail" (by 1900, originally U.S. college slang). Glass ceiling in the figurative sense of "invisible barrier that prevents women from advancing" in management, etc., is attested from 1988.
cel (n.): "celluloid sheet for an animated cartoon," from celluloid; became current by c. 1990 when they became collectible.
celadon (n.): "pale grayish-green," 1768, from French Céladon, name of a character in the romance of "l'Astrée" by Honoré d'Urfé (1610); an insipidly sentimental lover who wore bright green clothes, he is named in turn after Greek Keladon, a character in Ovid's "Metamorphoses," whose name is said to mean "sounding with din or clamor." The mineral celadonite (1868) is so called for its color.
celeb (n.): colloquial shortening of celebrity "celebrated person," by 1908, American English.
Celebes: old name for modern Sulawesi (which itself might be a native corruption of Celebes) in Indonesia, first used by Portuguese, 1512, perhaps from Os Célebres "the famous ones," a name given by navigators to the dangerous capes on the island's northeast coast.
celebrant (n.): 1731, from French célébrant "officiating clergyman" or directly from Latin celebrantem (nominative celebrans), present participle of celebrare (see celebrate).
celebrate (v.): mid-15c., originally of the Mass, from Latin celebratus "much-frequented; kept solemn; famous," past participle of celebrare "assemble to honor," also "to publish; sing praises of; practice often," originally "to frequent in great numbers," from celeber "frequented, populous, crowded;" with transferred senses of "well-attended; famous; often-repeated." Related: Celebrated; celebrating.
celebrated (adj.): "much-talked-about," 1660s, past participle adjective from celebrate (v.).
celebration (n.): 1520s, "honoring of a day or season by appropriate festivities," formed in English from celebrate, or else from Latin celebrationem (nominative celebratio) "numerous attendance" (especially upon a festival celebration), noun of action from past participle stem of celebrare. Meaning "performance of a religious ceremony" (especially the Eucharist) is from 1570s; that of "extolling in speeches, etc." is from 1670s.