1. To play for or support, either secretly or openly, the opposing side in a given contest or debate. Refers to cricket and baseball terminology, meaning to be a batter for the other team during a game. While the senator continues to publicly denounce the proposed tax law, many feel that he is really batting for the other side.

2. To be attracted to or have sexual relations with people of the same sex; a euphemism for being homosexual. I asked Simone out on a date, but it turns out that she bats for the other side.