Arbitrator

Ar"bi*tra`tor (?), n. [L., fr. arbitrari: cf. F. arbitrateur.] 1. A person, or one of two or more persons, chosen by parties who have a controversy, to determine their differences. See Arbitration.

2. One who has the power of deciding or prescribing without control; a ruler; a governor.

Though Heaven be shut,
And Heaven's high Arbitrators sit secure.
Milton.

Masters of their own terms and arbitrators of a peace.
Addison.

Syn. -- Judge; umpire; referee; arbiter. See Judge.