Top Definition
*verb* pronounced coss-tah-sing

1. To hold an alcoholic drink for an inordinate amount of time.
2. To pretend to be drinking hoping no one sees that your alcoholic drink has been at the same level for a minimum of at least 40 minutes.
3. Challenging others to drinking contests in hope that they are too drunk to see you haven't been drinking at all.

Also see "Nursing"
Conner: "Dude, come on chump. Man up and just down that beer already!"
Milo: "Screw you bro! Don't challenge a Beerlympic champion when you've been kostasing your beer all night!"
by The Tang Bang Crew May 19, 2008

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