英语词源字典 - 在线词源网站

cadet (n.)[cadet 词源字典]: c. 1610, "younger son or brother," from French cadet "military student officer," noun use of adjective, "younger" (15c.), from Gascon capdet "captain, chief, youth of a noble family," from Late Latin capitellum, literally "little chief," hence, "inferior head of a family," diminutive of Latin caput "head" (see capitulum). "The eldest son being regarded as the first head of the family, the second son the cadet, or little head" [Kitchin].

Apparently younger sons from Gascon noble families were sent to French court to serve as officers, which gave the word its military meaning. In English, the meaning "gentleman entering the military as a profession" is from 1650s, and that of "student at a military college" is from 1775.[cadet etymology, cadet origin, 英语词源]
cadge (v.): "to beg" (1812), "to get by begging" (1848), of uncertain origin, perhaps a back-formation from cadger "itinerant dealer with a pack-horse," mid-15c., which is perhaps from early 14c. cadge "to fasten, to tie," which is of unknown origin.
Cadillac (n.): Cadillac Automobile Company, established in 1902 by Detroit engine-maker Henry Martyn Leland and named for Antoine de la Mothe Cadillac (1658-1730), French minor aristocrat and colonial governor who founded Detroit in 1701.
Cadiz: from Latin Gades (Greek Gadeira), from Phoenician gadir "fort, enclosure." Related: Gaditan (from Latin adjective Gaditanus).
Cadmean victory (n.): c. 1600, "victory involving one's own ruin," translating Greek Kadmeia nike, from Cadmus (Greek Kadmos), legendary founder of Thebes in Boeotia and bringer of the alphabet to Greece. Probably a reference to the story of Cadmus and the "Sown-Men," who fought each other till only a handful were left alive. Compare Pyrrhic (adj.1).
cadmium (n.): bluish-white metal, 1822, discovered 1817 by German scientist Friedrich Strohmeyer, coined in Modern Latin from cadmia, a word used by ancient naturalists for various earths and oxides (especially zinc carbonate), from Greek kadmeia (ge) "Cadmean (earth)," from Kadmos "Cadmus," legendary founder of Boeotian Thebes. So called because the earth was first found in the vicinity of Thebes (Kadmeioi was an alternative name for "Thebans" since the time of Homer).
cadre (n.): 1830, from French cadre, literally "a frame of a picture" (16c.), so, "a detachment forming the skeleton of a regiment" (1851), from Italian quadro, from Latin quadrum "a square" (see quadrille). The communist sense is from 1930.
caduceus (n.): 1590s, from Latin caduceus, alteration of Doric Greek karykeion "herald's staff," from karyx (genitive karykos) "a herald," from PIE *karu-, from root *kar- "to praise loudly, extol" (cognates: Sanskrit carkarti "mentions with praise," Old English hreð "fame, glory"). Token of a peaceful embassy; originally an olive branch. Especially the wand carried by Mercury, messenger of the gods, usually represented with two serpents twined round it.
cady (n.): "hat, cap," 1846, of unknown origin.
caecum (n.): 1721, from Latin intestinum caecum "blind gut," from neuter of caecus "blind, hidden," from Proto-Italic *kaiko-, from PIE *kehi-ko- "one-eyed," cognate with Old Irish ca'ech "one-eyed," coeg "empty," Welsh coeg-dall, Old Cornish cuic "one-eyed;" Gothic haihs "one-eyed, blind." So called for being prolonged into a cul-de-sac.
Caesar: c. 1200, see caesarian; Old English had casere, which would have yielded modern *coser, but it was replaced in Middle English by keiser, from Norse or Low German, and later in Middle English by the French or Latin form of the name. Cæsar was used as a title of emperors down to Hadrian (138 C.E.), and also is the root of German Kaiser and Russian tsar (see czar). He competes as progenitor of words for "king" with Charlemagne (Latin Carolus), as in Lithuanian karalius, Polish krol. In U.S. slang c. 1900, a sheriff was Great Seizer.
Caesar salad: 1952, said to be named not for the emperor, but for Cesar Cardini, restaurant owner in Tijuana, Mexico, who is said to have served the first one c. 1924.
Caesarea: Latin city name derived from Caesar, applied in honor of the emperors to some new and existing cities in the Roman Empire, including modern Kayseri, Turkey; Shaizar, Syria, and Cherchell, Algeria (representing a French spelling of an Arabic name based on a Berber garbling of the Latin word).
caesarean: see caesarian.
caesarian (n.): 1923, shortening of Caesarian section (1610s); supposedly from Caius Julius Caesar, who was said to have been delivered surgically, thus legend traces his cognomen to Latin caesus past participle of caedere "to cut" (see -cide).

But if this is the etymology of the name, it was likely an ancestor who was so born (Caesar's mother lived to see his triumphs and such operations would have been fatal to the woman in ancient times). And Pliny derives his cognomen from caesaries "head of hair," because the future dictator was born with a full one. Caesarian section may come directly from caesus.
caesium (n.): see cesium.
caesura (n.): 1550s, from Latin caesura, "metrical pause," literally "a cutting," from past participle stem of caedere "to cut down" (see -cide).
cafe (n.): 1802, from French café "coffee, coffeehouse," from Italian caffe "coffee" (see coffee). The beverage was introduced in Venice by 1615 and in France from 1650s by merchants and travelers who had been to Turkey and Egypt. The first public café might have been the one opened in Marseilles in 1660.
cafe au lait (n.): 1763, French café au lait, literally "coffee with milk," from lait "milk" (12c.), from Vulgar Latin lactis, from Latin lactis (see lactation).
cafeteria (n.): 1839, American English, from Mexican Spanish cafeteria "coffee store," from café "coffee" (see coffee) + Spanish -tería "place where something is done" (usually business). The ending came to be understood popularly as meaning "help-yourself" (as though café + -teria) and was extended to new formation with that sense from c. 1923.