a word of vague etymology, apparently a convergence of multiple words, given wide application in late 19c. and settling into its main modern meaning "floozie" from early 1920s, with a revival in 1980s.
Bimbo first appears as the name of an alcoholic punch, mentioned in newspapers from New York state (1837), Boston (1842), and New Orleans (1844, but as having come from Boston). It is usually made with arrack or rum or brandy, sometimes all of them. It is likely derived from earlier bumbo (1748) a synonym for punch (n.2) which may be from 17c. slang ben-bowse (strong drink) and in which case connected with rum. This sense of the word quickly fades, though it occasionally is on menus as late as 1895. The spelling change from bumbo to bimbo might have been the result of slang bumbo appearing in the 1823 edition of Grose's Classical Dictionary of the Vulgar Tongue, with the meaning "the negro name for the monosyllable [cunt]."
From 1860-1910, Bimbo as a proper name is frequent: It is the name or part of the name of several race horses, dogs, and monkeys, a circus elephant (perhaps echoing jumbo), and a jester character in a play. It is in the title of a three-act musical farce ("Bimbo of Bombay"), and the name of a popular "knockabout clown"/actor in England and several other stage clowns. Also it appears as a genuine surname, and "The Bimbos" were a popular brother-sister comedy acrobatics team in vaudeville.
A separate bimbo seems to have entered American English c. 1900, via immigration, as an Italian word for a little child or a child's doll, evidently a contraction of bambino "baby."
By 1919 it began to be used generally of a stupid or ineffectual man, a usage Damon Runyon traced to Philadelphia prize-fight slang. He wrote, that July, in a column printed in several newspapers, of a hotel lobby fist-fight between "Yankee Schwartz, the old Philadelphia boxer," and another man, which Schwartz wins.
"No Bimbo can lick me," he said, breathlessly, at the finish.
"What's a Bimbo?" somebody asked "Tiny" Maxwell, on the assumption that "Tiny" ought to be familiar with the Philadelphia lingo.
"A bimbo," said "Tiny," "is t-t-two degrees lower than a coo-coo—cootie."
The word does turn up in Philadelphia papers' accounts of prizefights (e.g. "Fitzsimmons Is No Bimbo," Evening Public Ledger, May 25, 1920). The male word bimbo continues to appear as a derogatory term for a thug or bully through the 1940s (compare bozo.)
By 1920 the female word with a sense of "floozie" had developed, perhaps boosted by "My Little Bimbo Down on Bamboo Isle," a popular 1920 song in which the singer (imploring the audience not to alert his wife) tells of his shipwreck "on a Fiji-eeji Isle" and his "bimbo down on that bamboo isle... she's got the other bimbos beat a mile." An article in Variety from 1920, reviewing a performance by singer Margaret Young of a song simply referred to as "Bimbo" tells: "The wise crackers laughed every time the title was mentioned for the slangists know that Bimbo has a unique meaning." This may be a reference to the earlier bumbo monosyllable. Other references through the 1920s suggest a sense similar to flapper or vamp, including Mae West's sexually aggressive Diamond Lil character being called a "Bowery bimbo."
The female word fell from common use after the 1930s, and in the 1967 Dictionary of American Slang, only the shortened form bim (attested by 1924) was regarded as worthy of an entry. It began to revive circa 1975; in the R rated 1983 film Flashdance it was the misogynistic villain's insult of choice for the female dancers. Its resurrection during 1980s U.S. political sex scandals led to derivatives including diminutive bimbette (1983) and male form himbo (1988).