1 definition by DMazzIV

Top Definition
The second knuckle in (heading towards the hand). Originating from the knuckle at which you stop at when inserting a digit into another's asshole.
Used to warm up/stretch out an asshole before anal sex.
I was playing ping-pong and the ball hit off my poop-knuckle.
by DMazzIV August 22, 2006

The Urban Dictionary Mug

Lotsa space for your liquids.

Buy the mug

The Urban Dictionary Mug

Lotsa space for your liquids.

Buy the mug

The Urban Dictionary Mug

Your favorite word on a white mug.

Create a mug

The Urban Dictionary Mug

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Buy the mug

The Urban Dictionary T-Shirt

Soft and offensive. Just like you.

Buy the t-shirt

The Urban Dictionary T-Shirt

Smooth, soft, slim fit American Apparel shirt. Custom printed. 100% fine jersey cotton, except for heather grey (90% cotton).

Buy the t-shirt