1.nounA person appointed, or chosen, by parties to determine a controversy between them; an arbitrator.
2.noun(with of) A person or object having the power of judging and determining, or ordaining, without control; one whose power of deciding and governing is not limited.
"Television and film, not Vogue and similar magazines, are the arbiters of fashion."
3.nounA component in circuitry that allocates scarce resources.