The penis, specifically during the act of fellatio.
Sally liked playing the pink trombone behind the bleachers, after class.
by reiver September 06, 2005
1 more definition
noun. Slang for penis, dick, cock, etc., specifically when being fellated.
"Man, he ain't interested in your sister -- he only plays the pink trombone."
by Elwood P. Dowd December 29, 2006