Just launched! Learn slang while watching funny vids: urbandictionary.tv
1. fuck butt
Having an unusually shaped ass resulting directly from the only exercise that person receives is legs up in the air missionary sex. Usually sported by middle-aged house wives who sing kareoke at your local bar on Thursday nights.
I could tell before she even turned around that she was a fuck butt.
2. Fuck Butt
to fuck a butt. also used for conflict enders.
"hey get the fuck out of my house bro"!

"hey why dont you jus fuck butt"!
3. fuck butt
The nasty smell of your butt after having sex.
Man, you have a nasty case of fuck butt. - time to take a shower.