ARBITER

a presiding justiciary who must be a minister appointed to the Chaplain's Court Unit. The chaplain (or the permanent or part time assisting arbiter) presides over all court hearings and renders judgment. (HCO PL 5 Aug 66 II)

a person with full power to judge or decide.literally, a person who has the sole or absolute power of judging or determining. Used figuratively in this sense.