A word that was created by some half drunk, half stoned jackass in a club. Pretty much the most commonly used word in the entire goddamn universe. Made immortal by Justin Beiber (A half drunk, half stoned jackass) and now used not only to describe a person who is a complete and utter shitbird, but also used as an alternate word for, "Mental Defect."
"Did you hear that little asshat with his pants hanging down around his knees?"
"Ah, he said 'swag' like seven times in one sentence."