Lavatubing 

Walking, hiking, crawling, or climbing through an ancient lava tube which is now free of lava flow, such as Ape Cave at Mount St. Helens. Probably involves the use of headlamps or flashlights.

Guy 1: "Hey man, what did you do this weekend?"
Guy 2: "Went lavatubing. It was awesome, I got cave bacteria all over my hands."

Lavatubing by anthroubc2010 October 1, 2010

lavating 

Verb. To make use of the lavatory.

"Dude, where is Josh? He is 'sposed to be here for this meeting?"

"I think he is lavating. Hope he washes his hands."

lavating by Sputicus June 20, 2007