bustyoudaoicibaDictYouDict[bust 词源字典]
bust: There are two different words bust in English. The one meaning ‘break’ [18] is simply an alteration of burst. Bust ‘sculpture of head and chest’ [17] comes via French buste from Italian busto ‘upper body’, of uncertain origin (Latin had the temptingly similar bustum ‘monument on a tomb’, but this does not seem to fit in with the word’s primary sense ‘upper body’).

In English, application of the word to the human chest probably developed in the 18th century (one of the earliest examples is from Byron’s Don Juan 1819: ‘There was an Irish lady, to whose bust I ne’er saw justice done’), although as late as the early 19th century it could still be used with reference to men’s chests, and had not become particularized to female breasts: ‘His naked bust would have furnished a model for a statuary’, Washington Irving, A tour on the prairies 1835.
[bust etymology, bust origin, 英语词源]
bust (n.1)youdaoicibaDictYouDict
1690s, "sculpture of upper torso and head," from French buste (16c.), from Italian busto "upper body," from Latin bustum "funeral monument, tomb," originally "funeral pyre, place where corpses are burned," perhaps shortened from ambustum, neuter of ambustus "burned around," past participle of amburere "burn around, scorch," from ambi- "around" + urere "to burn." Or perhaps from Old Latin boro, the early form of classical Latin uro "to burn." Sense development in Italian is probably from Etruscan custom of keeping dead person's ashes in an urn shaped like the person when alive. Meaning "bosom" is by 1884.
bust (n.2)youdaoicibaDictYouDict
variant of burst (n.), 1764, American English. For loss of -r-, compare ass (n.2). Originally "frolic, spree;" sense of "sudden failure" is from 1842. Meaning "police raid or arrest" is from 1938. Phrase ______ or bust as an emphatic expression attested by 1851 in British depictions of Western U.S. dialect. Probably from earlier expression bust (one's) boiler, by late 1840s, a reference to steamboat boilers exploding when driven too hard.
bust (v.)youdaoicibaDictYouDict
"to burst," 1806, variant of burst (v.); for loss of -r-, compare ass (n.2). Meaning "go bankrupt" is from 1834. Meaning "break into" is from 1859. The slang meaning "demote" (especially in a military sense) is from 1918; that of "place under arrest" is from 1953 (earlier "to raid" from Prohibition). In card games, "to go over a score of 21," from 1939. Related: Busted; busting.