look up any word, like sex:
 
1.
To get really fat.
I ran into my ex the other day, damn she blew up.
by Bluesoju January 22, 2012
 
2.
when a guy blows up in his pants. he fills his pants with cum
barby:did you pee yourself?
ken:no i blew up
by apple crisp September 19, 2005