Green’s Dictionary of Slang

1. an unpleasant or contemptible person, one who cannot be trusted.

1894		Ade Stories of the Street and of the Town (1941) 33: Everybody that’s on to him says he’s a fink [...] a stiff, a skate.
1903		Ade People You Know 60: Anyone who goes against the Faculty single-handed is a Fink.
1914		Jackson & Hellyer Vocab. Criminal Sl. 33: fink [...] An unreliable confederate or incompetent sympathizer.
1929		E. Booth Stealing Through Life 259: ‘That guy,’ someone said, ‘is a rat.’ Another [...] added: ‘So’s the fink with him.’.
1938		D. Runyon ‘Cemetery Bait’ in Runyon on Broadway (1954) 521: A 22-carat fink, a fink being a character who is lower than a mudcat’s vest pocket.
1949		N. Algren Man with the Golden Arm 325: A little knock-kneed, gin-mill fink.
1958		Mad mag. Sept.–Oct. 11: We think Santa Claus is a fink.
1963		in T.I. Rubin Sweet Daddy 80: You’re just a fink [...] like all the other shitty bastards.
1970		(con. 1950s) H. Junker ‘The Fifties’ in Eisen Age of Rock 2 (1970) 102: She would certainly be turned off if he were [...] a fink.
1985		E. Leonard Glitz 193: They never go into any detail, they say here’s the name of the fink, do him.
1996		Penguin Bk of More Aus. Jokes 259: We do not refer to Judas as El Finko.

2. a strike-breaker, a company policeman.

1914		Jackson & Hellyer Vocab. Criminal Sl. 33: Fink, [...] an unreliable confederate or incompetent sympathizer.
1926		Amer. Mercury Jan. 63/1: Dating from the famous Homestead strike of 1892 is the odious fink. [It] according to one version was originally Pink, a contraction of Pinkerton, and referred to the army of strikebreakers recruited by the detective agency.
1927		(con. 1911) H. Asbury Gangs of N.Y. 361: A distinct class of men arose [...] earning high wages as strike breakers. They were called finks.
1935		J. Conroy World to Win 208: The college boys who came into the plant were usually finks.
1941		F.S. Fitzgerald Last Tycoon (1949) 143: A fink? That’s a strike-breaker or a company tec.
1958		‘Ed Lacy’ Room to Swing 41: He could make a fair living, even big money, if he wanted to be a rat and labor fink.
1970		‘Red’ Rudensky Gonif 69: One tall hillbilly tried to come after me one day for ‘joining in with the power mad finks and rackets!’.
1977		J. Sayles Union Dues (1978) 212: You got caught out as a company fink and your life expectancy took a big drop.

3. a contemptible object or thing.

1971

B. Moyers Listening to America 220: This led some of the protesters to conclude that I was a member of the comission and an equally abominable establishment fink.

4. an informer.

1925		K. Mullen ‘Westernisms’ in AS I:3 151: ‘Fink’ and ‘stool’ and ‘fly-dick’ designate the plain-clothes men.
1928		R.J. Tasker Grimhaven 33: ‘There never was six gees got together in the world without at least one of them being a cat!’ ‘Cat?’ ‘Sure. A fink, stool-pigeon.’.
1935		D. Lamson We Who Are About to Die 106: The cons take it for granted that you are a fink — one who bears tales in secret, a stool pigeon.
1940		R. Chandler Farewell, My Lovely (1949) 33: Now he’s looking for the fink that turned him up eight years ago.
1952		W.R. Burnett Vanity Row 46: ‘Hargis, I guess I don’t have to tell you I’m no fink [...] I did ninety days once just because I wouldn’t help the boys out’.
1963		B. Hecht Gaily, Gaily 104: I stood casually near them, listening in on the family chitchat, when one of them suddenly bellowed, ‘A newspaper fink! Get him!’.
1972		G.V. Higgins Friends of Eddie Coyle 118: Then what’ve you got? One machinegun salesman and one dead fink.
1986		C. Stroud Close Pursuit (1988) 92: All your finks are still out looking to score.
1996		S. Frank Get Shorty [film script] Well, you had it down cold. [...] Even the fink part. I never met a fink and I hope to God I never do, but how you did it must be the way finks act.
2001		OnLine Dict. of Playground Sl. 🌐 fink n.v. someone who rats on a friend or another child by passing information relating to a misdemenour of some sort to an adult, e.g. ‘You rat-fink!!’ (a supposedly more mature term).
2021		J. Ellroy Widespread Panic 12: He [...] riddled the ranks with a phalanx of finks to sniff out miscreants and misconduct.

5. (US Und.) a confidence trickster’s victim.

1940

D. Maurer Big Con 143: Never advance political views unless the fink asks you to do so.

6. (US, also fink-out) an act of backing down.

1967

New Yorker 24 June 43: The cop-out is like fink-out, only more graceful. It is getting away with a renege.