A word that was once originally cool, a shortened form of swagger, or a meter of one's "coolness." This was, of course until it was blatantly overused by 14-year old girls thinking they are cool by overusing the word "swag." It is best used only once a week, or else people think you are a fag from saying "swag" too much.
Random girl: Hey Jessica those are some pretty cool shoes!
Jessica: Oh yeah. Swag.
Random girl: That doesn't even make sense...
A more polite way to say "suck my dick". Literally translates to "suck my dick please". It is not usually used to actually tell someone to suck your dick, but used as a troll weapon or as a form of trash talk over online FPS chat boxes.
Fag: LULZ you just got pwned noob. smdplz!!1 (suck my dick please)
Regular person: Wow you're a fag. And no I will not.