When after sitting on something for a long time while working up a sweat or working up a sweat in general your ass sweats to a rediculous amount to the point where your underwear/boxers stick to your ass. Often accompanied by a funny walk.
After playing handball in gym nate had very bad swamp ass.
Logan: nate why are your pants still down hurry up we can't be late to class
Anthony: I recon he has dat dar swamp ass
Nate: airing my ass out, feels good man
Logan: yup I got it too. Sucks
Logan: nate why are your pants still down hurry up we can't be late to class
Anthony: I recon he has dat dar swamp ass
Nate: airing my ass out, feels good man
Logan: yup I got it too. Sucks
by CTU_FieldAgent200 December 08, 2009
Man, I bet that fat bitch been sitting in the sun so long in those fat-ass pants she gots herself a serious case of swamp-ass.
by Marko October 23, 2002
It was a hot summer day and James was taking a nap. Dave had just got back from playing basketball and had some major swamp ass, so he decided to share the wealth by giving James a swamp asstache!
by nello April 03, 2006
The unfortunate occurrence when one's ass gets sweaty, itchy and smelly usually after a low-quality dump or when another dump is impending. This often occurs in hot weather situations. Swamp ass can also occur when one is holding back flatulence or avoiding taking a dump in a filthy bathroom.
I had Indian food for lunch then got all sweaty walking home and have a nasty case of swamp ass. I need a shower and a butt-wipe. Dude I have the worst swamp ass right now but there's no way I'm taking a dump in that place.
by Fred S. Tare May 30, 2014
a very sweaty smelly ass
ben's swamp ass was so bad, he had to change his boxers 4 times in a single day. We replied, "holy shit, that's some swamp ass."
by dick head September 19, 2004
On a hot summer day or after physical activity when the massive amount of perspiration in your post-rectal region causes great discomfort. Often leads to moist underwear and a terrible odor.
by fantomelt February 23, 2009
by Pitt Rules Bitch February 10, 2003