Swag as slang-
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)."
Other uses-
Swag Stick, a short cane carried by a military officer.
Sources: Websters Dictionary and Wikipedia.
1: "That man's got some serious swagger!"
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."
Contrary to popular belief, SWAG actually stands for Sex With Alex Gaskarth. Alex Gaskarth is the singer of pop punk band All Time Low.
Person 1: Justin Bieber has so much SWAG!
Person 2: Bieber has Sex With Alex Gaskarth? I knew he was gay...
justin bieber wants to be a nigger so he likes to say swag alot and he is gay so it is a secret saying of what he really is.
the word teenage boys/girls, such as justin bieber. tend to use too often
im too lazy to put a definition, swag