To declare immense dominance over an opponent or a situation with exclamation and enthusiasm. It combines ownage and omg by combining the two O's of each word.
The visiting team just O2MG'd the home team in basketball today.
1. Select a player (real or fantasy) during a sports draft to spite or anger one or more of your opponents because they had intended to select him/her.
2. Select a player (real or fantasy) during a sport draft to put one or more of your opponents at a strategic disadvantage.
1. Billy hate drafted Chad OchoCinco because he knew Sam had wanted him since he is from Cincinnati. Billy already had plenty of players to fill that position but wanted to make sure Sam didn't get him.
2. Billy hate drafted Peyton Manning because he was the only good quarterback left and he knew Sam had been planning on drafting him.