Green’s Dictionary of Slang

1. to hit, esp. on the nose or head, to knock out.

1821		Egan Boxiana III 338: Spring however conked his opponent, when they closed.
1926		Derby Dly Teleg. 7 Apr. 3/3: Schoolboy slang [...] to hit — bash, conk.
1933		R. Chandler ‘Blackmailers Don’t Shoot’ Red Wind (1946) 112: If I didn’t get conked out of hand, I might learn who was who.
1939		E. O’Brien One Way Ticket 73: The steam gauge is over there, and the first time you let the steam drop or the water get outa sight I’ll konk ya with this monkey wrench.
1946		‘Uncle Newton’ Ups and Downs of Newsy Wapps Bk 1 31: I squirm and wriggle and fuss and she ‘Kunks’ me in my head.
1946		Mezzrow & Wolfe Really the Blues 70: Mac would conk the ugly customers on the top and carry them outside.
1951		Kerouac On the Road (The Orig. Scroll) (2007) 180: I don’t like that fairy at the bar [...] I think I’ll get up and conk him.
1953		A.J. Liebling Honest Rainmaker (1991) 114: I am lucky that he did not konk me with the cane.
1964		H. Selby Jr Last Exit to Brooklyn 100: She relaxed and gave it thought. Cant konk im here.
1977		R. Coover Public Burning (1979) 271: The b-girl retaliates by conking him over the head with another beer bottle.
1986		O. Senior ‘The Boy Who Loved Ice Cream’ Summer Lightning 85: Stan still yu jumbo-head bwoy or a konk yu till yu fenny.
1991		B. Hamper Rivethead (1992) 111: I wondered what approach he might have taken had it been his own grandmother konked silly and heaped on the Rivet Line floor.
1996		H. Roth From Bondage 281: The newspapers were just as full today as they were when he was conked on the bean with newspaper bludgeons.
2001		J. Stahl Plainclothes Naked (2002) 106: No doubt he’d just as soon have conked an old lady for her pin money.
2012		A. Bergen ‘Dread Fellow Churls’ in Crime Factory: Hard Labour [ebook] I’m not surprised my quarry nutted me out first, tiptoed up behind me and conked me on the skull.

2. (US) to kill.

1918		E.M. Roberts Flying Fighter 334: Conked. A new word which is taken from the Russian language and which means stopped or killed.
1926		J.J. Finerty Criminalese.
1938		E.H. Price ‘Revolt of the Damned’ in Double-Action Gang June 🌐 ‘Luck?’ ‘Uhuh. Number ten conked,’ Benny reported.
1942		D.X. Manners ‘Fifty-Grand Funeral’ in Ten Detective Aces Dec. 🌐 You haven’t had a client since Cain conked Abel.
1948		H. McCoy Kiss Tomorrow Goodbye in Four Novels (1983) 105: He was yellow. That’s what caused him to get conked.

3. in fig. use, i.e. to burden with, to assail.

1946

Charleston (WV) Daily Mail 2 Sept. 6/5: Me schmaltzy gabber couldn’t red a Chicago piano rap, so the D.A. conks me with a whole mag.

4. see conk (out) v.