Grundle is another word for chad: the region between the balls and the arse-hole; can be an erogenous zone for some.

Girl: I was fingering that part between his balls and his arse and there was shit there.
Everyone listening remained silent but later laughed among themselves:
'Eww! He had a shitty chad.'

When you measure your dick, you don't start at the arse-hole and include the chad; you risk getting shit on your measuring tape.
Q: What on earth is a grundle?
A: You know, the chad, the part between balls and arse.
by Chane. March 27, 2020
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The act of burrowing your nose into someones anus durring sexual playtime. A gluteal motor boat. Also known as a "Steam Boat Willy".
We started with the Dutch rudder, then moved on to the Dirty Sanchez, and ended with a lengthy and lively Grundle.
by Tasty time May 21, 2012
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The trashiest excrements of trailer park septic tanks, which, when mixed with crack-cocaine form into an American of sub-average intelligence, and are of the lowest societal and economic standing possible, ever.
Is that grundle pregnant, again? Shoot, it looks like her dad forgot to wear a condom, again.
by greedy grundle groper February 22, 2010
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A noun used to define the sticky build up found underneath the scrotum. Build up increases when the persons doesn't shower or has had hot sweaty day.
Person 1: Yo J-Kwon, take a wiff of this.
Person 2: Damn! What the hell is that on your fingers.
Person 1: I haven't showered in days, and that's some of my wicked bad grundle build up from my fat ball sack.
by Flo$$y B May 31, 2005
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noun: The sweat off your balls.
The guitar picks stink of Dave's grundle and tiger balm!
by Metal Maniac February 26, 2006
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A Jewish Grandma Troll often in an irate mood. Known to inhabit bridge underpasses in Palestine.
I was accosted by a shockingly hairy grundle as I made my way home from the meat market.
by katiethelady March 13, 2015
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The butter that grows under your thighs after a hot monday morning.
Usually found on the fat female species with a high tolerance to cottage cheese thighs.
Dude, that chick had a shitload of grundle growing under your thighs!
by Grundle Master 5000 February 16, 2009
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