Top Definition
an activity taking place amongst highschoolers, in which you...

1. steal someone's backpack while they leave it unattended.
2. remove its contents.
3. turn the sack entirely inside-out.
4. replace the items.
5. re-zip it.
when the owner of the backpack returns, they will most likely be very irritated with you. but they will get over it.
what are you doing to his backpack?" - "we're ninja-sacking it!
by ashleyvennum December 06, 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