Etymology From Old French duc, through Middle English duk, duke, from Latin dux, ducis. Displaced native Old English heretoga. Was present as duc in late Old English, from the same Latin source. Doublet of doge, duc, duce, and dux. Ultimately from Proto-Indo-European *dewk-, which is also the source of the second component in German Herzog. The “fist” sense is thought to be Cockney rhyming slang where “Duke(s) of York” = fork. Fork is itself Cockney slang for hand, and thus fist.
1
The male ruler of a duchy (female equivalent: duchess).
2
The sovereign of a small state.
3
A high title of nobility; the male holder of a dukedom.
4
A grand duke.
5
Any of various nymphalid butterflies of the Asian genera Bassarona and Dophla.
“Your friend sure knows how to use his dukes. Biff, bang! One, two, and the copʼs on his ass!”1952, Ralph Ellison, Invisible Man, Penguin Books (2014), page 438:
1 more example
"How did the sport go." "O sparred a few rounds. Let the instructor have a few on the button." "You must be tough." "I can handle my dukes."1963, J P Donleavy, A Singular Man, published 1963 (USA), page 19:
Etymology From Old French duc, through Middle English duk, duke, from Latin dux, ducis. Displaced native Old English heretoga. Was present as duc in late Old English, from the same Latin source. Doublet of doge, duc, duce, and dux. Ultimately from Proto-Indo-European *dewk-, which is also the source of the second component in German Herzog. The “fist” sense is thought to be Cockney rhyming slang where “Duke(s) of York” = fork. Fork is itself Cockney slang for hand, and thus fist.
Percy’s military career began in France under Dukes Henry and John of Lancaster; […]2001, John Cannon, editor, A Dictionary of British History, Oxford University Press, published 2004, →ISBN: