An arbiter is a person or institution that judges and settles a quarrel between two other people or groups.
例句
He was the ultimate arbiter on both theological and political matters.他在神學和政治事務上都是最終的仲裁人。...the court's role as arbiter in the law-making process.法庭在制定法律過程中擔任裁決機構的角色
N-COUNT
（時尚或風格的）權威，決定者
An arbiter of taste or style is someone who has a lot of influence in deciding what is fashionable or socially desirable.
例句
Sequins have often aroused the scorn of arbiters of taste.閃光裝飾片經常引起時尚引領者的鄙視。