1.) an ass man; someone who digs the booty; a lover of posterior; someone afflicted with booty cooties
2.) someone who likes to go in through the out door; someone on a mission to uranus; etc.
bro #1: what's up with that dude? he's always with some fuckin' scary looking slampig with a hardcore butterface and shit.
bro #2: oh, he don't care about nothing above the waist, he's a rump junkie, yo.
sir mix-a-lot, marv albert, daryl hall, rocco siffredi, cosmo kramer