agonist

Definition

Someone involved in a contest or battle (as in an agon), protagonist.

Etymology

Borrowed from Latin agōnista, from Ancient Greek ἀγωνιστής (agōnistḗs, “combatant, champion”). By surface analysis, agon or agony + -ist.

Example Sentences

• "When bending the elbow, the biceps is the agonist."
• "Acetylcholine is an agonist at the cholinergic receptor."