Top Definition
The act of fellatio performed on a man who is having a bowl movement on the toilet. iow, giving head to a guy while he's taking a huge dump.

Referenced briefly in the american pie: beta house movie, wherein a test to join a fraternity includes the requirement of receiving said carnal pleasure.

could possibly refer to the act performed on a woman, but the logistics are much more complicated
"Yo, your mom gave me some grundleingus last night."

"Dude, thats gross."

"no, what's gross is that i had just eaten some taco bell"
by _lou_ July 10, 2008
Free Daily Email

Type your email address below to get our free Urban Word of the Day every morning!

Emails are sent from We'll never spam you.