Green’s Dictionary of Slang

to finish off, to destroy.

1846		Swell’s Night Guide 124/1: Kyboshery, to gammon, to flat, to swindle.
1879		‘’Arry on Niggers’ in Punch 15 Mar. 113/2: He’s off with the 17th Lancers to kibosh the festive Zulu.
1885		Bulletin (Sydney) 2 May 12/3: ’Spose yer thort there wos nothin’ to do / But to load up and pull at yer triggers; / But there’s lots more to learn before you / Can be trusted to ‘kibosh’ the niggers.
1896		‘’Arry on African Affairs’ in Punch 22 Feb. 90/1: True the Rads and ’Ome Rulers are kiboshed, and clean off their crumpets with spite.
1910		‘Doss Chiderdoss’ ‘Spy Glasses’ Sporting Times 17 Sept. 2/2: He imagined that he was a patriot bold / With a mission to ‘kybosh’ all spies.
1911		Out West Oct. 241: But where, oh where did ‘put one over,’ ‘kibosh,’ [...] and a thousand and one other of their ilk come from?
1921		Gloucester Citizen 1 June 3/6: Ze barbarians! Zay even kibosh ze cuisine.
1934		J. Franklyn This Gutter Life 172: O you fool! Now you’ve kyboshed any chance there was of getting something from him!
1967		‘Whisper All Aussie Dict.’ in Kings Cross Whisper (Sydney) xxxv 6/3: kibosh: A dampener. To put a stop to anything. To halt a lurk.
1982		J. Ellroy Clandestine 222: I kiboshed the thought: don't think, Underhill, I said to myself as I locked the car, or this thing [...] will eat you up.
1990		(con. early 1950s) J. Ellroy L.A. Confidential 3: The Cohen contract kiboshed an outright dope sale.
2002		J. Ellroy ‘The D.A.’ in Destination: Morgue! (2004) 150: Parker kiboshed LAPD corruption.
2021		J. Ellroy Widespread Panic 110: I nudged her knees and kibioshed it [i.e. an attempt at seduction].