It is essentially the most anti-creative, anti-intellectual and classless habit of modern proletariat.
Crystal: No, what?
Anthony: I'm a little worried. He works for $7.30/hr 30 hours a week at Arby's. He just bought a SWAGGER Camo & Chambray shirt on his fourth credit card even though he's got $13275 in debt and is getting hassled by collections agencies all day long. What kind of sense does that make?
Crystal: Oh hell yeah, that SWAGGER jump off! He ain't care. Stop hating, jealous bitch, wish you had swag.
Swag has two meanings.
1. Illegally acquired goods.
2. to sway or sag. Like a Hanging Swag Lamp/light. Remember those horrible glass grape lights from the 60's at grandma's house? Those are a type of swag lights.
Pirates used it in old movies and books, which leads me to believe it only got popular because of losers who jumped on the shitty pirate bandwagon since PotC came out. The same goes for all of those other "new" and "cool" words/sayings; some douche bag copied it and pretended it was original. Come on people just look at TV, originality is dead and people are just ripping of works of those long dead, since the dead can't sue.
Back at their hideout, the pirates split the swag between them.
Swag, slang originating in the early 1800s for stolen goods or booty; possibly carried by a swagman
Swag, slang originating from the Scottish slang word "swagger" which was a description of the way some Scots walk (in a swaying motion). The word was altered in the English language to mean "the way one presents oneself".
Swag, promotional items given away at trade fairs and events
The phrase "He/She has swag." only makes literary sense if taken as follows: "He/She has (a way to present oneself as an individual)."
Swag Stick, a short cane carried by a military officer.
Sources: Websters Dictionary and Wikipedia.
2: "Don't point it out! Maybe he has a gimp leg or something."
1: "Or he's Scottish?"
2: "With a peg-leg?"
1: "That must be it."