Main entry: agonist
Definition: (biochemistry) a drug that can combine with a receptor on a cell to produce a physiological reaction
Main entry: agonist
Definition: a muscle that contracts while another relaxes
Usage: when bending the elbow the biceps are the agonist
Main entry: agonist
Definition: someone involved in a contest or battle (as in an agon)
Main entry: agonist, protagonist
Definition: the principal character in a work of fiction