Snitch
/snɪtʃ/
noun
A thief.
An informer, usually one who betrays his group.
A nose.
Synonyms: grass, mole, rat, stool pigeon, bite, snap, snippock, schnozz
verb
To inform on, especially in betrayal of others.
To contact or cooperate with the police for any reason.
To steal, quickly and quietly.
Synonyms: drop a dime, grass up, rat out, filch, pilfer, pocket