late 14c., agent noun from knock. Sense of "door banger" is by 1590s. Knockers "a woman's breasts" is slang attested from 1941.
A woman's breasts; hooters: Dumb broads with big knockers, that's what guys go for (1941+)
A consistently negative critic; detractor: that pack of knockers that have been howling (1898+)
Related TermsA very important person; big shot, macher: Knocker means a big shot, either real or imagined, and you pronounce that first ''k''
[1960s+; fr Yiddish, literally ''one who cracks or snaps a whip'']