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"
A person to whom the authority to settle or judge a dispute is delegated.
"After their contract negotiations stalled, the two companies agreed to let an independent arbitrator decide who was at fault for the delay."