When you stay in wet clothing (usually swimming trunks) for to long, you're butt begins to itch.
Thus causing you to scratch it profusely, often ending in you looking like a monkey.
Dude, I went swimming and never dried myself off, now I have the worst case of monkey butt ever!
A term used to describe a man or woman who can grow hair fully, and to a substantial length on the buttocks.
Before the hair transplant, Roy was a Monkey Butt.
Term of endearment: Can be used to describe a significant other or a loved one in a silly way.
I love you Monkey Butt!!
Teenage girls gather up/bunch up thier shirts in the back and secure the shirt's ponytail with a rubber band or the like.
When we were at the mall we passed a group of girls all sporting monkey butts.
The condition resulting from inadequate wiping of the anus following defecation, which can cause the afflicted to appear monkey-like as they dig in their butt, trying to appease the itching.
"Man I have a severe case of monkeybutt. I need to use your bathroom for a few minutes."
a prolapsed arse, resembling that of a baboons arse or any other of those wonderful red arsed primates we descend from.
After removing the bulbous 12" butt plug she had a very impressive case of monkey butt.
When your ass gets all sweaty and chaffed from recieving too much anal sex.
Best when a banana is used and the act is performed in your brand new kitchen.
Jeff Misner has the nastiest monkey butt i've ever seen.