I know you rappers is about a dime
Two possible meanings:
He could be talking about a dime like money, saying rappers only rap for money.
Or he could be saying a dime like a woman who is a perfect ten, saying rappers only rap to get bitches.
He’s saying that most of these other rappers are a “dime a dozen”, common, trashy and cheap.
To help improve the meaning of these lyrics, visit “Hop Madness” by Hopsin Lyrics and leave a comment on the lyrics box