Swag is a mainstream rap movement about the way someone carries his or herself in a manner that glorifies alcohol/drugs, misogyny, and gaudy and ostentatious attire with extremely poor lyrical content and condescension.
Soulja Boy: Hop on out that bed! Turn my swag on! Yeah, I'm gonna make money!
It's Soulja Boy Tell 'Em, I roll with Shawty Lo
I got so much snow, Gucci head to toe
Chain on chill, watch on freeze
So much ice I got lookin' like Chinese
Someone listening: Holy crap... this is so terrible. Swag has to leave rap music.
This big ol' watch cost more than yours
I built a house you can't afford
It's stupid big, got an ocean view
It's way up there, I look down on you
Someone listening: This is. . . . so condescending. Why are pro-swag rappers so fucking offensive? Turn it off!