1. a person chosen to settle a dispute or decide a matter
2. a person who has the power to decide what is acceptable or fashionable

Examples

• The neutral arbiter helped resolve the contract dispute.
• Both parties agreed to accept the arbiter’s decision as final.
• She served as an arbiter in the labor negotiations.
• The fashion magazine considers itself an arbiter of style.
• He became the arbiter of good taste in the art world.
• The court appointed an independent arbiter to handle the case.
• As arbiter of the competition, she had to remain completely impartial.