The "Oh,no!" lumps in a fart that you knew in advance that you shouldn't have risked, due to recent diarrhea.
I felt the fartnuts, and knew that I had to go home to change my shorts.
by Phuqit October 14, 2009
When you fart so hard that it wiggles your nuts.
Oh man, you just ripped a fart nut!
by Laura March 14, 2005
when u try to do a fake fart, and it doesnt work, u have unintentionaly created a fart nut( when u shit in your pants and leave an annoying turd stain)
he was trying to be funny, but all he got was a fart nut
by slapapig September 23, 2003