before vowels cac-, word-forming element meaning "bad, ill, poor" (as in cacography, the opposite of calligraphy and orthography), from Latinized form of Greek kakos "bad, evil," considered by etymologists probably to be connected with PIE root *kakka- "to defecate." The ancient Greek word was common in compounds; when added to words already bad, it made them worse; when added to words signifying something good, it often implies too little of it.

"itch for doing something," 1560s, from Latinized form of Greek kakoēthēs "ill-habit, wickedness, itch for doing (something)," from kakos "bad" (from PIE root *kakka- "to defecate") + ēthē- "disposition, character" (see ethos). Most famously, in Juvenal's insanabile scribendi cacoethes "incurable passion for writing."

"a name rejected for linguistic reasons, bad nomenclature in botany or biology," 1888, from caco- "bad, ill, poor" + -onym "name" (from PIE root *no-men- "name").

large, flat bean from an African shrub, 1846, from some African word.

1650s, "harsh or unpleasant sound," probably via French cacophonie (16c.), from a Latinized form of Greek kakophonia, from kakophonos "harsh sounding," from kakos "bad, evil" (from PIE root *kakka- "to defecate") + phonē "voice, sound," from PIE root *bha- (2) "to speak, tell, say." The meaning "discordant sounds in music" is from 1789. Related: Cacophonous.

c. 1600, in the classical sense, "cardoon, artichoke," from Latin cactus, from Greek kaktos, name of a type of prickly plant of Sicily (the Spanish artichoke), a "foreign word of unknown origin" [Beekes]. In reference to the green, leafless, spiked American plants from 1769. Linnaeus gave the name to them thinking they were related to the classical plant. Related: Cactal.

1730, shortening of cadet (q.v.); originally used of servants, then (1831) of town boys by students at Oxford and English public schools (though at Cambridge it meant "snob"), then "townsman" generally. Compare caddie. The 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]

"pertaining to the valuation of landed property as a basis for taxation," 1850, 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."

"a dead body, a corpse," late 14c., from Latin cadaver "dead body (of men or animals)," probably from a perfective participle of cadere "to fall, sink, settle down, decline, perish," from PIE root *kad- "to fall." Compare Greek ptoma "dead body," literally "a fall" (see ptomaine); poetic English the fallen "those who have died in battle."

early 15c., "gangrenous, mortified;" 1620s "of or belonging to a corpse;" 1660s, "looking like a corpse;" from Latin cadaverosus "corpse-like," from cadaver "dead body" (see cadaver). Related: Cadaverously; cadaverousness.