Top definition
When you've been holding your pee for literally more than 3 hours so when you finally do release your pee, you don't have to push it out, it just flows.
Dude, I was at that party all night, and when I got home, I had to take a fat piss.
by Hollywood8245 November 03, 2007
Get the mug
Get a Fat piss mug for your grandma Julia.