agonist (n.) Look up agonist at Dictionary.com
1876, in writings on Greek drama, "a hero (attacked in the play by an antagonist)," from Latin agonista, Greek agonistes "rival combatant in the games, competitor; opponent (in a debate)," also, generally "one who struggles (for something)," from agonia "a struggle for victory" (in wrestling, etc.), in a general sense "exercise, gymnastics;" also of mental struggles, "agony, anguish" (see agony). Agonistes as an (ironic) epithet seems to have been introduced in English by T.S. Eliot (1932).