Top Definition
The muscle you develop between your forearm and bicep on the arm of the hand you masturbate with.
John: Hey broski, wanna hang tonight?

Joe: Ehh... I dunno, I was really gonna work on toning my masturbating muscle tonight.

John: Oh.. I getcha, I worked on it last night.
by aaronthejoo April 20, 2011

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