Green’s Dictionary of Slang

cold-cock v.

also cold-caulk
[SE (out) cold, unconscious/knock cold under knock v.]

to knock unconscious; thus cold-cocker n.; cold-cocked adj., unconscious.

[US]H. Simon ‘Prison Dict.’ in AS VIII:3 (1933) 25/2: COLDCOCK. 1, v. To knock unconscious, usually with a blackjack.
[US](con. 1917) J. Stevens Mattock 44: Why the hell ain’t you showed some of this cold-cockin’ stuff before? [Ibid.] 231: You open up, come clean [...] or by the holy old hell you’ll get coldcocked so your mother won’t know you.
[US]D.M. Garrison ‘Song of the Pipeline’ in Botkin Folk-Say 110: Then I cold-cocks him and [...] he flops and sprawls out on the ground.
[US]W.R. Burnett High Sierra in Four Novels (1984) 415: He and another guy cold-cocked a man and clipped him for five hundred.
[US]L. Uris Battle Cry (1964) 213: You go up and coldcock him.
[US]W. Styron Set This House on Fire 438: You’d have thought Mason had been cold-cocked with a wrench.
[US]P. Hamill Deadly Piece 51: Someone got in the house and coldcocked me.
[US]W. Diehl Hooligans (2003) 404: How do we do this? We just cold-cock the son of a bitch or what?
[US]C. Hiaasen Strip Tease 127: Crandall gazed at the coldcocked candidate.
[US]N. McCall Makes Me Wanna Holler (1995) 68: Did you see that niggah’s face when I hit him? I cold-cocked his ass!
[US]T. Dorsey Stingray Shuffle 301: Serge pulled a pistol [...] and coldcocked one over the head.
[US]G. Pelecanos Way Home (2009) 53: he was the crazy white boy who had cold-cocked a kid for no reason.
[US]‘Jack Tunney’ Split Decision [ebook] I cold-cocked a fat guy in a hat.