drummer’s butt
n.— «We used to joke about playing long hours and getting “drummers’ butt,” also referred to as “swamp ass.” When I played rock on a vinyl covered throne I’d get, well, uh, sweaty. This can be a real pain in the…, especially if you don’t get to take a shower immediately after playing.» —“Re: hemrrhoids and drumming” by Colin Odden Usenet: rec.music.makers.percussion Mar. 9, 1998. (source: Double-Tongued Dictionary)