pumpin' the rump Share definition Flag engaging in the act of butt-fucking, or picercing the giblets. I got done fuckin' the pussy and then I truned her over and started pumpin' the rump. pumpin' the rump by Bill B. July 4, 2005 0 0 Get merch Get the pumpin' the rump mug. Buy Now — $32.95 See more merch