A person who is fat, thus liking McDonalds or any Food and has done something really mean, stupid or gay.
"Guy #1: Yo see that fat guy over there? He was messin around with your girlfriend
Guy #2: WOW, what a McFag! Im Gunna kill him!"
Guy #2: WOW, what a McFag! Im Gunna kill him!"
by PwnzYouAll April 23, 2010