an informer, such as one working for the police; spy
3.
an unpleasant, disappointing, or contemptible person
verb
4. (intransitive; often foll byon)
to inform (on someone), as to the police
Word origin
C20: of uncertain origin
fink in American English
(fɪŋk)
US
noun Slang
1.
an informer
2.
a strikebreaker; esp., a professional strikebreaker
3.
a person regarded as contemptible, obnoxious, etc.
verb intransitive
4. Slang
to inform (on)
Idioms:
fink out
Word origin
Ger, lit., finch, used since the 17th c. as generalized pejorative; adopted (c. 1740) by students at Jena for nonmembers of fraternities (prob. in allusion to thewild bird in contrast to the caged canary); later extended to those not in organizations,esp. unions