| 1. | the leading character, hero, or heroine of a drama or other literary work. |
| 2. | a proponent for or advocate of a political cause, social program, etc. |
| 3. | the leader or principal person in a movement, cause, etc. |
| 4. | the first actor in ancient Greek drama, who played not only the main role, but also other roles when the main character was offstage. Compare deuteragonist, tritagonist. |
| 5. | Physiology. agonist. |
s actor who plays the first part, lit., first combatant, equiv. to prôt(os) first + agōnist
s one who contends for a prize, combatant, actor. See proto-, antagonist 
The principal character in a literary work. Hamlet, for example, is the protagonist of the play by William Shakespeare that bears his name.
protagonist
in ancient Greek drama, the first or leading actor. The poet Thespis is credited with having invented tragedy when he introduced this first actor into Greek drama, which formerly consisted only of choric dancing and recitation. The protagonist stood opposite the chorus and engaged in an interchange of questions and answers. According to Aristotle in his Poetics, Aeschylus brought in a second actor, or deuteragonist, and presented the first dialogue between two characters. Aeschylus' younger rival, Sophocles, then added a third actor, the tritagonist, and was able to write more complex, more natural dialogue. That there were only three actors did not limit the number of characters to three because one actor would play more than one character
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