arbiter

1. A person appointed, or chosen, by parties to determine a controversy between them; an arbitrator.
2. A person or object having the power of judging, determining, or ordaining; one whose power of deciding and governing is not limited. · Television and film, not Vogue and similar magazines, are the arbiters of fashion.
3. A component in circuitry that allocates scarce resources.
4. The person who oversees a chess match and ensures the rules are followed.

الجمع arbiters