A vocal utterance that signals anyone more culturally sophisticated than an orangutan to pick you up and throw you off a cliff for the good of all mankind, even when used jokingly. Similar middle school esque blurps include "swag", "yolo", "snap", "gangsta", "raped", and "owned".
Jason: My girlfriend dumped me, but at least I got accepted into UFV
Bryan: Oh burn
Jason: You're 28, uneducated, work at Wal-Mart, live with your mom, and you talk your balls just dropped. You aren't in any position to be "burning" anyone. Ever.
A sunburn or suntan focused on the left arm. It is caused by the left side of the body being the only half that gets exposed to sunlight while driving. Presumably, it would be located on the right side of the body in countries where they drive on the left side of the road.