Online Etymology Dictionary

C: third letter of the alphabet. Alphabetic writing came to Rome via the southern Etruscan "Caeretan" script, in which gamma was written as a crescent. Early Romans made little use of Greek kappa and used gamma for both the "g" and "k" sounds, the latter more frequently, so that the "k" sound came to be seen as the proper one for gamma. To restore a dedicated symbol for the "g" sound, a modified gamma was introduced c. 250 B.C.E. as G. In classical Latin -c- has only the value "k," and thus it passed to Celtic and, via Irish monks, to Anglo-Saxon, where -k- was known but little used.

In Old French, many "k" sounds drifted to "ts" and by 13c., "s," but still were written with a -c-. Thus the 1066 invasion brought to the English language a more vigorous use of -k- and a flood of French and Latin words in which -c- represented "s" (as in cease, ceiling, circle). By 15c. native English words with -s- were being respelled with -c- for "s" (as in ice, mice, lice). In some words from Italian, meanwhile, the -c- has a "ch" sound (a sound evolution in Italian that parallels the Old French one). In German, -c- in loanwords was regularized to -k- or -z- (depending on pronunciation) in the international spelling reform of 1901, which was based on the Duden guide of 1880.
C.E.: as an abbreviation for "Common Era" or "Christian Era," and a non-Christian alternative to A.D., attested from 1838 in works on Jewish history. Companion B.C.E. is attested from 1881.
C.O.D.: abbreviation of cash on delivery, 1859, originally American English.
c/o: addressing abbreviation for care of; "common" by 1889.
ca.sa.: abbreviation of Latin capias ad satisfaciendum, a writ issued upon a judgment in a personal action for the recovery of money (see capias).
cab (n.): 1826, "light, horse-drawn carriage," shortening of cabriolet (1763), from French cabriolet (18c.), diminutive of cabrioler "leap, caper" (16c./17c.), from Italian capriolare "jump in the air," from capriola, properly "the leap of a kid," from Latin capreolus "wild goat, roebuck," from PIE *kap-ro- "he-goat, buck" (source also of Old Irish gabor, Welsh gafr, Old English hæfr, Old Norse hafr "he-goat"). The carriages had springy suspensions.

Extended to hansoms and other types of carriages, then extended to similar-looking parts of locomotives (1851). Applied especially to public horse carriages, then to automobiles-for-hire (1899) when these began to replace them.
cabal (n.): 1520s, "mystical interpretation of the Old Testament," later "society, small group meeting privately" (1660s), from French cabal, in both senses, from Medieval Latin cabbala (see cabbala). Popularized in English 1673 as an acronym for five intriguing ministers of Charles II (Clifford, Arlington, Buckingham, Ashley, and Lauderdale), which gave the word its sinister connotations.
cabala (n.): 1670s, variant of cabbala. Related: Cabalist.
cabalistic (adj.): 1670s; see cabal + -istic.
caballero (n.): 1877, "a Spanish gentleman," from Spanish caballero, from Latin caballarius, from caballus "a pack-horse, nag, hack" (see cavalier (n.)). Equivalent of French chevalier, Italian cavaliere.
cabana (n.): 1898, western U.S., from American Spanish cognate of cabin (q.v.).
cabaret (n.): 1650s, "tavern, bar, little inn," from French cabaret, originally "tavern" (13c.), which is of uncertain origin, perhaps from Middle Dutch cambret, from Old French (Picard dialect) camberete, diminutive of cambre "chamber" (see chamber (n.)). The word was "somewhat naturalized" in this sense [OED]. It was borrowed again from French with a meaning "a restaurant/night club" in 1912; extension of meaning to "entertainment, floor show" is by 1922.
cabbage (n.): mid-15c., caboge, from Middle French caboche "head" (in dialect, "cabbage"), from Old French caboce "head," a diminutive from Latin caput "head" (see capitulum). Introduced to Canada 1541 by Jacques Cartier on his third voyage. First written record of it in U.S. is 1660s.

The decline of "ch" to "j" in the unaccented final syllable parallels the common pronunciation of spinach, sandwich, Greenwich, etc. The comparison of a head of cabbage to the head of a person (usually disparaging to the latter) is at least as old as Old French cabus "(head of) cabbage; nitwit, blockhead," from Italian cappuccio, diminutive of capo.
cabbala (n.): 1520s, from Medieval Latin cabbala, from Mishnaic Hebrew qabbalah "reception, received lore, tradition," especially "tradition of mystical interpretation of the Old Testament," from qibbel "to receive, admit, accept." Compare Arabic qabala "he received, accepted."
cabbalistic (adj.): 1620s, from cabbala + -istic.
cabbie (n.): also cabby, "cab-driver," 1859, from cab (n.) + -ie. Also see taxi (n.).
caber (n.): pole used in housebuilding, especially as an object tossed in the Highland games, 1510s, from Gaelic cabar "pole, spar," cognate with Irish cabar "lath," Welsh ceibr "beam, rafter."
cabernet (n.): family of grapes, or wine made from them, 1833, from French. Supposedly the best of them, cabernet sauvignon is attested in English from 1846.
cabin (n.): mid-14c., from Old French cabane "hut, cabin," from Old Provençal cabana, from Late Latin capanna "hut" (source of Spanish cabana, Italian capanna), of doubtful origin. French cabine (18c.), Italian cabino are English loan-words. Meaning "room or partition of a vessel" (set aside for use of officers) is from late 14c. Cabin fever first recorded by 1918 in the "need to get out and about" sense; earlier (1820s) it was a term for typhus.
cabinet (n.): 1540s, "secret storehouse, treasure chamber," from Middle French cabinet "small room" (16c.), diminutive of Old French cabane "cabin" (see cabin); perhaps influenced by (or rather, from) Italian gabbinetto, diminutive of gabbia, from Latin cavea "stall, stoop, cage, den for animals" (see cave (n.)).

Meaning "case for safe-keeping" (of papers, liquor, etc.) is from 1540s, gradually shading to mean a piece of furniture that does this. Sense of "private room where advisors meet" (c. 1600) led to modern political meaning (1640s); perhaps originally short for cabinet council (1630s); compare board (n.1) in its evolution from place where some group meets to the word for the group that meets there.
cabinet-maker (n.): 1680s, from cabinet + maker.
cabinetry (n.): 1857, from cabinet + -ry.
cable (n.): c. 1200, from Old North French cable, from Medieval Latin capulum "lasso, rope, halter for cattle," from Latin capere "to take, seize" (see capable). Technically, in nautical use, a rope 10 or more inches around, to hold the ship when at anchor; in non-nautical use, a rope of wire (not hemp or fiber). Given a new range of senses in 19c.: Meaning "message received by telegraphic cable" is from 1883 (short for cable message). Cable car is from 1879. Cable television first attested 1963; shortened form cable is from 1972.
cable (v.): c. 1500, "to tie up with cables;" 1871, American English, "to transmit by cable;" from cable (n.). Related: Cabled; cabling.
cablese (n.): 1895, from cable in the telegraphic sense + -ese as a language name suffix. "Since cablegrams had to be paid for by the word and even press rates were expensive the practice was to affix Latin prefixes and suffixes to make one word do the work of several" [Daniel Schorr], such as exLondon and Londonward to mean "from London," "to London" (non-Latin affixes also were used). Hence the tale, famous in the lore of the United Press International, of the distinguished but harried foreign correspondent who reached his breaking point and wired headquarters UPSTICK JOB ASSWARD. Its economy and expressive power fascinated Hemingway in his newspapering days.
cabochon (n.): 1570s, from French cabochon (14c.), augmentative of caboche (12c.), augmentative or pejorative formation, ultimately from Latin caput "head" (see capitulum). Essentially the same word as cabbage.
caboodle (n.): c. 1848, see kit and caboodle.
caboose (n.): 1747, "ship's cookhouse," from Middle Dutch kambuis "ship's galley," from Low German kabhuse "wooden cabin on ship's deck;" probably a compound whose elements correspond to English cabin and house (n.). Railroading sense is by 1859.
cabriolet (n.): "light two-wheeled chaise," 1766, from French cabriolet (18c.), derivative of cabriole (see cab). So called from its light, leaping motion.
caca (n.): "excrement," a nursery word but a very ancient one (PIE *kakka-), forming the base word for "excrement, to void excrement" in many Indo-European languages, such as Greek kakke "human excrement," Latin cacare, Irish caccaim, Serbo-Croatian kakati, Armenian k'akor; Old English cac-hus "latrine."

Etymologists dispute whether the modern Germanic words (Dutch kakken, Danish kakke, German kacken), are native cognates or student slang borrowed from Latin cacare. The word in this form appears in English slang c. 1870, and could have been taken from any or several of the languages that used it (Spanish, Modern Greek).
cacao (n.): seed from which cocoa and chocolate are made, 1550s, from Spanish cacao, from Nahuatl (Aztecan) cacaua, root form of cacahuatl "bean of the cocoa-tree."
cacciatore (adj.): by 1973, from Italian, literally "hunter," from past participle of cacciare "to hunt, chase" (see chase (v.)).
cache (n.): 1797, "hiding place," from French Canadian trappers' slang, "hiding place for stores" (1660s), a back-formation from French cacher "to hide, conceal" (13c., Old French cachier), from Vulgar Latin *coacticare "store up, collect, compress," frequentative of Latin coactare "constrain," from coactus, past participle of cogere "to collect" (see cogent). Sense extended by 1830s to "anything stored in a hiding place."
cache-sexe (n.): 1926, French, from cacher "to hide" (see cache) + sexe "genitals" (fem.); see sex (n.).
cachectic (adj.): 1630s, from Latinized form of Greek kakhektikos "in a bad habit of body" (see cachexia).
cachet (n.): 1630s, Scottish borrowing of French cachet "seal affixed to a letter or document" (16c.), from Old French dialectal cacher "to press, crowd," from Latin coactare "constrain" (see cache). Meaning evolving through "(letter under) personal stamp (of the king)" to "prestige." Compare French lettre de cachet "letter under seal of the king."
cachexia (n.): "bad general state of health," 1540s, from Latinized form of Greek kakhexia "bad habits," from kakos "bad" (see caco-) + -exia, related to exis "habit or state," from exein "to have, be in a condition," from PIE root *segh- "to hold, hold in one's power, to have" (see scheme (n.)). Related: cachexic.
cachinnate (v.): "to laugh loudly or immoderately," 1824, from Latin cachinnatum, past participle of cachinnare (see cachinnation). Related: Cachinnated; cachinnating.
cachinnation (n.): "loud laughter," 1620s, from Latin cachinnationem (nominative cachinnatio) "violent laughter, excessive laughter," noun of action from past participle stem of cachinnare "to laugh immoderately or loudly," of imitative origin. Compare Sanskrit kakhati "laughs," Greek kakhazein "to laugh loudly," Old High German kachazzen, English cackle, Armenian xaxanc'.
cack: "act of voiding excrement; to void excrement," mid-15c., from Latin cacare (see caca). Related: Cacked; cacking.
cackle (v.): early 13c., imitative (see cachinnation); perhaps partly based on Middle Dutch kake "jaw," with frequentative suffix -el (3). Related: Cackled; cackling. As a noun from 1670s. Cackleberries, slang for "eggs" is first recorded 1880.
caco-: before vowels cac-, word-forming element meaning "bad, ill, poor" (as in cacography, the opposite of calligraphy), from Latinized form of Greek kako-, from kakos "bad, evil," considered by etymologists probably to be connected with PIE *kakka- "to defecate" (see caca). The ancient Greek prefix was common in compounds; when added to words already bad, it made them worse; when added to words signifying something good, it implies too little of it.
cacoethes (n.): "itch for doing something," 1560s, from Latinized form of Greek kakoethes "ill-habit, wickedness, itch for doing (something)," from kakos "bad" (see caco-) + ethe- "disposition, character" (see ethos). Most famously, in Juvenal's insanabile scribendi cacoethes "incurable passion for writing."
cacoon (n.): large, flat bean from an African shrub, 1854, from some African word.
cacophony (n.): 1650s, from Greek kakophonia, from kakophonos "harsh sounding," from kakos "bad, evil" (see caco-) + phone "voice, sound," from PIE root *bha- (2) "to speak, tell, say" (see fame (n.)). Related: Cacophonous.
cactus (n.): c. 1600, from Latin cactus "cardoon," from Greek kaktos, name of a type of prickly plant of Sicily (the Spanish artichoke), perhaps of pre-Hellenic origin. Modern meaning is 18c., because Linnaeus gave the name to a group of plants he thought were related to this but are not.
cad (n.): 1730, shortening of cadet (q.v.); originally used of servants, then (1831) of town boys by students at British universities and public schools (though at Cambridge it meant "snob"). Meaning "person lacking in finer feelings" is from 1838.
A cad used to be a jumped-up member of the lower classes who was guilty of behaving as if he didn't know that his lowly origin made him unfit for having sexual relationships with well-bred women. [Anthony West, "H.G. Wells: Aspects of a Life," 1984]
cadastral (adj.): 1858, from French cadastral, from cadastre "register of the survey of lands" (16c.), from Old Italian catastico, from Late Greek katastikhos "register," literally "by the line" (see cata-, stair). Gamillscheg dismisses derivation from Late Latin capitastrum "register of the poll tax."
cadaver (n.): c. 1500, from Latin cadaver "dead body (of men or animals)," probably from a perfective participle of cadere "to fall, sink, settle down, decline, perish" (see case (n.1)). Compare Greek ptoma "dead body," literally "a fall" (see ptomaine); poetic English the fallen "those who died in battle."
cadaverous (adj.): "looking like a corpse," early 15c., from Latin cadaverosus "corpse-like," from cadaver (see cadaver). Related: Cadaverously; cadaverousness.