brown bag that 

literally: to put in a brown bag.
most frequently in reference to alcoholic substances (ie: 40's)

also, Young Religious Unitarian Universalists brown bag their drugs, illegal/hazardous materials during the time they spend at conferences.

Dude, let's get that homeless guy to buy us some 40's and sit on the corner brown bagging 'em.

Dude, you should SO brown bag that.

brown bag that by Joe Shmoe May 25, 2003