[proh-tag-uh-nist] 
| 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 + agōnists 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.