1. The act of your turd going down the drainpipe aka. take a dump.
2. To smoke a tiny bud of weed from a pipe. Usually for the purpose of quickly getting a little blitzed before the task at hand.
Jake: I had to pipe a nug cuz you blazed without me dude.
Kevin: Oh. Seemed like you were gone for long...
Jake: Haha, I also swung by the washrooms quickly to pipe a nug too.