1. Stolen Without A Gun - in the concert industry this term refers to promotional items distributed normally at a concert to roadies and employees of the concert company (although most concert companies were merged into "SFX Entertainment" from 1997-2000 and later sold off to "Clear Channel Communications" which also owns large majority of U.S. radio stations.) People have made up many other explanations for this acronym, but this is the original meaning according to many people within the music industry.
2. The belongings of Australian bushman which they rolled and carried while traveling by foot.
3. Scientific ass wild guess - This acronym was popular in the 1980's, meaning a highly accurate guess not backed up with scientific evidence.
2. The Aborigines traveled with their swag.
3. I listened to his swag and it made lots of sense.
Darrel: You got so much dick in your ass
Assface Magee: Fuck you, SWAG
Me: 'That's because you're a fucking retard trying to be like the rest of the try hards thinking their dumb ass have swag.'
The word quickly made its way to the states and has ever since become the catchphrase of douchbags and tools everywhere.
Person 2: "You're a dick"