Available Definitions:
1) n. - A person to whose sole decision a controversy or question between parties is referred; especially, one chosen to see that the rules of a game, as cricket, baseball, or the like, are strictly observed.
2) n. - A third person, who is to decide a controversy or question submitted to arbitrators in case of their disagreement.
3) v. t. - To decide as umpire; to arbitrate; to settle, as a dispute.
4) v. t. - To perform the duties of umpire in or for; as, to umpire a game.
5) v. i. - To act as umpire or arbitrator.