ACTOR
actor. 1. One who acts; a person whose conduct is in question. 2.Archaic. A male plaintiff.
3.Hist. An advocate or pleader; one who acted for another in legal matters. Cf. REUS(1).4.Roman
law. (ital.) A person who sues; a claimant. — Also termed (in sense 4) petitor. Pl. (in sense 4)
actores.[Blacks Law 8th]