1 definition by jules442000

Top Definition
When you fart, but the fart bubble moves up your inner-thigh instead of your ass, and pops when it reaches your balls.
Jim: Did you fart?
Michael: No, it came from my balls.
Jim: Oh, so it was a grundlefluff.
by jules442000 April 16, 2019

Mug icon
Buy a Grundlefluff mug!