- noun the most important character in a novel, play, story or other literary work
- The principal character in a play. In ancient Greece, thiswas the term for the principal actor. According to legend, Thespisbecame the first protagonist by expanding the role of the actor wholed the chorus in the dithyramb. The protagonist was subsequentlyjoined by the deuteragonist and the tritagonist(second and third actors) in the works of Euripides and Sophocles.