(1):
(v. i.) To act as umpire or arbitrator.
(2):
(v. t.) To perform the duties of umpire in or for; as, to umpire a game.
(3):
(v. t.) To decide as umpire; to arbitrate; to settle, as a dispute.
(4):
(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.
(5):
(n.) A third person, who is to decide a controversy or question submitted to arbitrators in case of their disagreement.