'fink' definitions:

Definition of 'fink'

From: WordNet
noun
Someone acting as an informer or decoy for the police [syn: fink, snitch, snitcher, stoolpigeon, stool pigeon, stoolie, sneak, sneaker, canary]
verb
Take the place of work of someone on strike [syn: fink, scab, rat, blackleg]
verb
Confess to a punishable or reprehensible deed, usually under pressure [syn: confess, squeal, fink]