Person A: hey did you hear that Tia became a youth pastor and told all her old lib friends they were on the devil's path?
Person B: Sounds like a Grass Back to me
Person A: Yeah, textbook case.
this is a person who is acting like an idiot, maybe they are being a pain in the arse. this is never a compliment and should only be used as a last resort in an arguement
A racist colloquialism originating in the north west of England, referring to a person of darker skin tone. It is thought to have originated from the whip marks on slaves' backs, which, from a distance, look like long blades of grass stuck to the back.