A real or ficticious condition afflicting a hot-tempered person. Used as an excused for mean-spirited remarks or action.
Watch out for Ken...he's got an ass rash and is gonna be hard to get along with today.
by Harry Flashman August 31, 2004
When you have an itch in your ass.
"Oh i got a bad assrash today"
by Bubba Smith jr September 18, 2006