ಅರ್ಥ : The principal character in a work of fiction.
ಸಮಾನಾರ್ಥಕ : protagonist
ಅರ್ಥ : Someone involved in a contest or battle (as in an agon).
ಅರ್ಥ : A muscle that contracts while another relaxes.
ಉದಾಹರಣೆ :
When bending the elbow the biceps are the agonist.
ಅರ್ಥ : (biochemistry) a drug that can combine with a receptor on a cell to produce a physiological reaction.