Definition of "fink"

fink¹

/fɪŋk/

noun
plural finks
1. (chiefly US, slang) A contemptible person.
2. (chiefly US, slang) An informer.
3. (chiefly US, slang) A strikebreaker.
verb
third-person singular simple present finks, present participle finking, simple past and past participle finked
1. (chiefly US, slang) To betray a trust; to inform on.
  Quotations
  “I move that we determine through a thorough investigation whether the new worker is a fink or no; and if he is a fink, let us discover who heʼs finking for!”
  1952, Ralph Ellison, Invisible Man, Penguin Books (2014), page 222

/fɪŋk/

verb
third-person singular simple present finks, present participle fought, simple past and past participle fought
1. (dialectal, th-fronting) Pronunciation spelling of think.

/fɪŋk/