-adjective
To possess ample enough diarrhea within one's body wherein it becomes humanly impossible to contain. After such an event, said "mud" escapes from the body usually attacking the underwear first, then outerwear...

The feeling of moist, itchy, clay-like fecal matter which remains in your anal cavity after sub-par wiping is the result of one having an extremely messy bowel movement and spending four to six hours perfroming physical activity in moderate to extreme heat. The aforementioned condition may or may not result in the dragging of ones bare anus on a coarse surface such as a carpet or snadpaper.

Mud butt is just another term for "Diarrea".

a severe case of diarrhea.

horrible runny shyt; anal leakage

A term used to describe when poop uncontrollably comes out of your booty hole after anal intercourse.

the true "definition" of mudbutt,(all the rest are other peoples versions) is: the condition of the anal region where ones crevice between the ass cheeks becomes hot and saucy due to sweat, buildup of underwear residue, and poor wiping abilities. It is almost certain to happen to anyone on a real hot summer day if they:
1)wear dirty and/or heavy clothes
2)do not shower
3)have recently deficated
4)have participated in exercise