look up any word, like tbt:
 
1.
When the muscles of the buttocks tighten up suddenly and unnecessarily, causing the feeling that the butt is under attack.
Often times this happens when you have to poop really bad.
John: Ah, butt attack!
Moses: You have to poop, man?
by purplecalculus June 26, 2011
 
2.
A vexing situation in life that is out of one's control. A negative turn in one's day.
Man, I can't believe I overdrew my damn checking account- talk about a massive buttattack.

A buttattack in the afternoon?!? Man I shouldn't have left my cellphone on the table.
by chicky22 April 07, 2009