1. (

• arbiter ,
• supreme_authority

) someone with the power to settle matters at will; "she was the final arbiter on all matters of fashion" ;

2. (

• arbiter ,
• arbitrator ,
• umpire ,

) someone chosen to judge and decide a disputed issue; "the critic was considered to be an arbiter of modern literature"; "the arbitrator's authority derived from the consent of the disputants"; "an umpire was appointed to settle the tax case" ;