Definition of "umpire"
umpire
/ˈʌm.paɪ.ə(ɹ)/
noun
plural umpires
(Australian rules football) A match official on the ground deciding and enforcing the rules during play. As of 2007 the Australian Football League uses three; in the past there were two or just one. The other officials, the goal umpires and boundary umpires, are usually referred to by those phrases.
(law) A person who arbitrates between contending parties.