Mule Knuckle  

Is the equivalent of a camel toe, but for guys. When your shorts or jeans ride up your crotch and you can see your nuts making a distinctive shape similar to that of a mules knuckle.

"Look at that guy sitting over there, he totally has a mule knuckle right now"

Mule Knuckle by c-money55 April 14, 2009

white knuckle ride 

The act of getting high by snorting cocaine placed on your knuckles.

Those knuckle-heads were on a white knuckle ride all night!

white knuckle ride by chitsb January 25, 2011

Cunt Knuckle 

A stimulated clitoris.

I knocked this girl's cunt knuckle so hard, she's still having an orgasm to this day!

Cunt Knuckle by micah November 29, 2004

Piss Knuckle

1. A name for a professional who is completely incompetent in his field. (ie an accountant in rural Kansas)

2. A tiny penis.

That damned piss knuckle did my taxes, and now I'm being audited by the IRS.

or

My piss knuckle hurts when I pee.

Piss Knuckle by derikny2 August 3, 2010

Trunk Knuckle 

Sticking a finger in someone's ass at least to the second knuckle of your finger of first knuckle of your thumb.

Hey, that dude really likes when his girl gives him a trunk knuckle around back while getting a blowie.

Trunk Knuckle by Sarcastication January 25, 2013

Gorilla Knuckle 

The outline of the edge of a guy's glans ridge through his underwear or pants.

Check out that guy's gorilla knuckle- he's got it pierced!

Gorilla Knuckle by merkinmuncher November 4, 2013

mewtons knuckle

When you're wearing a thong, and your balls are so saggy that each ball falls onto both sides of the thong creating newton ball like balls, and you have someone put their tongue in between both balls, and swing the balls together like newton balls. :)

i'm going to Mewtons Knuckle you so hard your taste buds will never work the same.

mewtons knuckle by Throbin Hood June 13, 2016