pro·tag·o·nist / prōˈtagənist; prō-/ • n. the leading character or one of the major characters in a drama, movie, novel, or other fictional text. ∎  the main figure or one of the most prominent figures in a real situation: in this colonial struggle, the main protagonists were Great Britain and France. ∎  an advocate or champion of a particular cause or idea: a strenuous protagonist of the new agricultural policy.

protagonist chief personage in a drama XVII; leading person in a contest or cause XIX. — Gr. prōtagōnistḗs, f. prôtos first + agōnistḗs combatant, actor, f. agōnízesthai contest; see -IST.