The action of taking a dump and humping it repeatedly for satifaction. This is a form of masturbation
Clint was vey satified after he dump-a-humped for several hours
Guy 1:"Dude have you ever tried dump-a-humping?"
Guy 2:"No how do you do it?"
Guy 1:"You take a dump then you hump it till you cumm inside of it and you feel satisfied!"