Ump (noun)

An umpire, a person who makes judgements and enforces rules in sports.

Origin:

Slang, origin unknown.

Examples:

1. The ump made the call that the runner was out at first base.
2. The ump is the official who makes the final decision on the rules of the game.
3. The players were arguing with the ump about the call he made.
4. The ump is responsible for making the calls on balls and strikes.
5. The ump is the authority on the field, his decision is final.