Short for Gas Assisted Poop, a situation in which the poop is forced out the ass using gaseous pressure in the colon, with little or no need for muscle assistance. Also known as Gas Propelled Poop (G.P.P.)
It was huge, but I hardly had to push because them beans made a good amounta gas behind it, so it were a G.A.P.!
by Jeralde July 27, 2008