> fink
> 
> fink fink, sb.2 U.S. slang. Origin unknown. A pejorative term of
> wide application, esp.
> 
> a. An unpleasant or contemptible person.
> 
> b. An informer; a detective.
> 
> c. A strike-breaker.
> 
>    * 1903 Ade People you Know 60 Anyone who goes against the Faculty
>      single-handed is a Fink.
> 
>    * 1914 Jackson & Hellyer Vocab. Criminal Slang 33 Fink,..an
>      unreliable confederate or incompetent sympathizer.
> 
>    * 1925 Amer. Speech I. 151/2 `Dick' and `bull' and `John Law'
>      have become established as names for the police, while `fink'
>      and `stool' and `fly-dick' denote the plain-clothes men.
> 
>    * 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.
> 
>    * 1929 E. Booth Stealing through Life xi. 259 `That guy..is a
>      rat.'.. `So's the fink with him.'
> 
>    * A. 1940 F. Scott Fitzgerald Last Tycoon (1949) vi. 143 A fink?
>      That's a strike-breaker or a company tec.
> 
>    * 1940 R. Chandler Farewell, My Lovely v. 25 Now he's looking for
>      the fink that turned him up eight years ago.
> 
>    * 1959 C. Williams Man in Motion viii. 106 Except for being a
>      rat, a fink, a scab, a thug, and a goon, he's one of the
>      sweetest guys you'll ever meet.
> 
>    * 1970 New Yorker 15 Aug. 66/2 The film, in sudden want of a
>      through-and-through-fink type, forgets that it has established
>      two..hippies as loyal.

> 
> fink
> 
> fink fink, v.1 Colloq. corruption of think v.2
> 
>    * 1888 Kipling Wee Willie Winkie (1890) 12, I don't fink I'll
>      ever want to kiss big girls.
> 
>    * 1913 B. Moore in E. Pertwee Reciter's Second Treasury Verse
>      226, I really fink, 'tween me and you, I'd raver be a little
>      girl.
> 
>    * 1941 H. G. Wells You can't be too Careful iii. ii. 115 That boy
>      is still as pure as the driven snow. (I don't fink. I saw his
>      face.)
> 
>    * 1962 N. Marsh Hand in Glove vi. 202 Makes you fink, don't it?

> fink
> 
> fink fink, v.2 U.S. slang. f. fink sb.2 intr. To inform on.
> 
>    * 1925 Flynn's 24 Jan. 119/1 Fink, to squeal; to inform on.
> 
>    * 1953 W. R. Burnett Vanity Row v. 43 Only a rat co-operated with
>      the police; only a rat finked!
> 
>    * 1953 R. Chandler Long Good-Bye ix. 57 Suppose you had to hire a
>      private eye... Would you want one that finked on his friends?
> 
>    * 1969 Rolling Stone 28 June 4/2 The gang tries to sell their
>      smack to a black hippie pusher who finks on them.