An adjective; used mainly in western culture by mentally undeveloped teenage, blond haired assholes obsessed with their crappy hairstyle and who are secretly homosexual.
The word describes the shitty use of clothing and prefuse, pointless spitting while checking their own reflection.
Jake: ben, you've got sweg mate!
Ben: yeah i know brov. (whilst fiddling with his genitles in a crowded street)