arbiter

This term conveys a sense of absolute authority and finality. When used in a legal or formal dispute, it suggests a neutral third party whose decision is binding and terminates the conflict. It carries a weight of impartiality and judicial power.

In social or aesthetic contexts, the word shifts toward influence and prestige. It describes an individual whose taste is so widely respected that they effectively define what is considered acceptable or desirable within a specific subculture or industry.