Top Definition
An individual who jacks off in class...generally to his respective teacher. (Abbreviated SB)
1. A: DUDE that guy is totally jacking off in class!!!
B: What do you expect...he's an SB

2. A: What do Semen Boys do?
B: Jack off in class....duh
by The Revealer of the Truth February 09, 2010

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