英语词源字典 - 在线词源网站

alligator (n.)[alligator 词源字典]: 1560s, lagarto (modern form attested from 1620s, with excrescent -r as in tater, feller, etc.), a corruption of Spanish el lagarto (de Indias) "the lizard (of the Indies)," from Latin lacertus (see lizard). Alligarter was an early variant. The slang meaning "non-playing devotee of swing music" is attested from 1936; the phrase see you later, alligator is from a 1956 song title.[alligator etymology, alligator origin, 英语词源]
hep (1): "aware, up-to-date," first recorded 1908 in "Saturday Evening Post," but said to be underworld slang, of unknown origin. Variously said to have been the name of "a fabulous detective who operated in Cincinnati" [Louis E. Jackson and C.R. Hellyer, "A Vocabulary of Criminal Slang," 1914] or a saloonkeeper in Chicago who "never quite understood what was going on ... (but) thought he did" ["American Speech," XVI, 154/1]. Taken up by jazz musicians by 1915; hepcat "addict of swing music" is from 1938. With the rise of hip (adj.) by the 1950s, the use of hep ironically became a clue that the speaker was unaware and not up-to-date.
jitterbug (n.): popular type of fast swing dance, 1938, American English, from "Jitter Bug," title of a song recorded by Cab Calloway in 1934. Probably the literal sense is "one who has the jitters" (see jitters; for second element see bug (n.) in the slang "person obsessed with" sense). Another sense current about this time was "swing music enthusiast." As a verb from 1938.