A derogatory term for any hard rock music. The term comes from a nationwide advertising campaign on hard rock radio stations in the 1990s that used the tagline "Rock. Nothing but Rock." Listeners quickly changed that to "Nothing Butt Rock". Though it refers to anything played on hard rock stations, it commonly is used to refer to 'hair-bands' or used by people to distinguish the 'bad' butt rock from the hard rock that they like.
He sat around stoned all day listening to butt rock on the 'Wild Hare'.