Rashing

(verb) The act of insulting (or roasting) someone so badly, it leaves a (figurative) rash on them.

Origins: The Edward Devotion School, Brookline, around 2011

Person 1: Damn I didn't know the Haitian earthquake was so bad it got around to your hairline too. That shit's fucked up.

Person 2: Shut up white trash, I'ma stop on your nutz if you keep talking.

Background characters: OH SHIT THEY'RE RASHING THE FUCK OUTTA EACH OTHER!!!!