A drawn out series of runny, nasty, liquidy bowel movements, usually composed more of stomach bile than fecal matter, and most often quite messy and splattery.
I had dinner at a hole in the wall Mexican place last night and the butt faucet has beenrunning ever since.
A fart which is so loud and powerful that it reverberates the entire area around the expeller.
Robin: Oh my God, everything in the house is shaking, it's an earth quake!
Chris: Don't worry about it, that was just a butt quake I let loose downstairs.
Local Newscaster: Today we mourn the loss of the twenty people that were killed on this day last year when an unsuspecting local man released a butt quake while on board a city bus.