The act of listening to dubstep on the toilet to increase and rhythm of excretion.
Tim: "Hey Robby, what took you so long in the bathroom"
Robbie: "Sorry, I got kind of into my Dumpstep"
Tim: "What the fuck?"
Robbie: "I said Dumpstep"
When you listen to Dubstep while taking a shit.
I was at school and heard Dubstep coming from the stall, the kid was taking a shit. that day Dumpstep was created.