Most likely a bag (of weed) worth $20. Aka a dub, 20 sack, or many other hip terms for a smallish quantity of weed. The size of the bag of course depends on the quality of the shit.

-peace
Lightitup44 Reviewed by Lightitup44 on . What is a 20 bag? What exactly is a 20 bag? I have no clue. Rating: 5