Umpire
Part of speech: noun
Definition: The official who presides over a tennis game sat on a high chair. One of the two white-coated officials who preside over a cricket match. One of usually 4 officials who preside over a baseball game. The official who stands behind the line on the defensive side. A match official on the ground deciding and enforcing the rules during play. As of 2007 the Australian Football League uses 3, or in the past 2 or just 1. The other officials, the goal umpires and boundary umpires, are normally not called just umpires alone.
Part of speech: verb
Definition: To act as an umpire in a game.
Referee
Part of speech: verb
Definition: To act as a referee.
Part of speech: noun
Definition: An umpire or judge; the official who makes sure the rules are followed during a gameA person who settles a disputeA person who writes a letter of reference for someoneAn expert who judges the manuscript of an article or book to decide if it should be published