An umpire or judge; an official who makes sure the rules are followed during a game.

“The referee kicked Jim out of the game for fighting.”

A person who settles a dispute.

A person who writes a letter of reference or provides a reference by phone call for someone.

“Your application, along with letters from three referees, should be received by January 31.”

To act as a referee.

“He has to referee three hockey games this weekend.”