slang abbreviation for Undercover Cop. A policeman who dresses in street clothes attempting to hide his identity so that he can fit in with tha crowd and get the word on happenins the police wouldn't normally know about. Tries to act like yor boy but then sells you out so he can bust a drug deal or anythin like that.
T-Bill: "yo, yous gotta hit it up with that new dude jimmy, he fa real!"
The Stepbrother: "nah man, dat fools a cuvvie, stay away from him."