An acronym for Red Anarchist Skinheads. The RASH are one of many different groups of skinheads. Members of this group contain: anarchists, communists, marxists, and other extreme lefts. The RASH reject all forms of racial prejudice and have no toleration for Nazis.
guy 1: Look at Eduardo, he's a skinhead who hates blacks, mexicans, and other minorities.
That guy that follows you around, thinks he's friends with you, and doesn't understand when you tell them you want them to leave. Comes from the traditional form of rash, which is irritating and also difficult to remove.
Guy 1: Hey, wanna catch up this weekend?
Guy 2: Sure.
Rash : Cool, when are we meeting?
Guys 1 & 2 : Fucking rash.