Definitions

1. noun

A substance that binds to a receptor, usually in a way that mimics the action of a natural agonist; a molecule that activates a cellular receptor.

“The agonist in the new medication binds to the opioid receptors in the brain, producing a pain-relieving effect.”

2. noun

An actor who plays the main or starring role in a play, film, or television show; a performer who has the lead role.

“The talented agonist in the movie stole the show with her dramatic performance.”