nut flap

to move your hips up and down in a humping motion so that your scrotum swings up and down giving the appearance of your "nuts flapping".

I saw robert in the hall today doing the nut flap.

nut flap by Alden aka Ginger July 28, 2008

nut flapping 

Occurs when your testicles smack together when running down the stairs in gym shorts

dude i was so embarassed today i had some major nut flapping going on when i was running down the stairs

nut flapping by peterbattista November 2, 2006

Nut Flapper 

The astronomical phenomenon that occurs when a male farts in a certain position that causes the gust of air from the anus to rush under his scrotum and create a flapping motion

Dude i just laid a nut flapper.

Nut Flapper by Aliocac September 27, 2015

nutflap 

The leftover skin of the scrotum after a man gets his testicles removed, so the "flap" of skin from the "nut"sack.

"So how did Jim's surgery go?"
"They couldn't save his balls because of the impact of all those fish, so they had to settle with the nutflap."

nutflap by ReaCtioNz December 23, 2014

Nutflap 

A insult or a disease where one gets a flap in there nuts like a shark fin

Scott: “Oh I’ve got nutflap as the disease my doctor diagnosed me with it”
Jenson: “good you but face”

Nutflap by OOPLAH911 October 3, 2023

NutFlaps 

Nuts that wave in the wind when hung out to dry.

Wow did you hear the sound of those Nutflaps!

NutFlaps by scarymuff March 6, 2025