Being at a certain point of desperation where you'll reach over to another table and help yourself to the unfinished drink of someone who's left the lounge. Common practice of stressed-out folks about to head into a sales call, going through divorce, or just want to put the "seed" in "seedy", and need that extra drink. Usually practiced after one has had a couple of drinks (to, ya know, establish that you "belong" in the establishment), and desperately reaches for some abandoned beverage in a knee-jerk, fuck-all gesture.
"Dude--drinking that beer that guy left is pretty dirtbag."
"You wanna go get drinks later--maybe a bit of dirtbagging?"
Dirtbagging. verb. To attend and event or establishment with the general wardrobe, demeanor, attitude and behavior of a typical dirtbag.
Standard dirtbag attire includes: wifebeaters, flannel shirts, old 1980s rock band t-shirts, cut-off jean shorts or ripped pants.
Guy 1: Man, we so dirtbagged that fancy restaurant last night!
Guy 2: Really?
Guy 1: Yeah, everyone was wondering why the fuck we were there. We got super hammered on the the cheapest beer they had, too!
Guy 2: dirtbagging is so awesome.
To quite literally, shovel shit down someones throat, whether they like it or not. They dont stand a chance if you're a dirt bagger, they wont stop till you've either A. Passed out from the smell, or B. Urinated yourself from the fear of what they might do. Dirtbagging occasionally includes a spade and hand cuffs, though it doesnt have to.
drinking the last few mouth fulls left in people's drinks in a pub or at a party without their permission because you haven't got your own drink, usually done by young teenagers or people who've had way too much