umpire

(tennis, badminton) The official who presides over a tennis match sat on a high chair.

(cricket) One of the two white-coated officials who preside over a cricket match.

(baseball) One of the officials who preside over a baseball game.

(American football) The official who stands behind the line on the defensive side or next to the referee on the offensive side.

(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.

(curling) The official who presides over a curling game.