agonist

/ˈægənəst/

Other forms: agonists

Definitions of agonist

1. noun

   someone involved in a contest or battle (as in an agon)
   antonyms:

   antagonist

   someone who offers opposition

   type of:

   contestant

   a person who participates in competitions
2. noun

   the principal character in a work of fiction
   synonyms: protagonist

   example of:

   character, fictional character, fictitious character

   an imaginary person represented in a work of fiction (play or film or story)

   types:

   antihero

   a protagonist who lacks the characteristics that would make him a hero (or her a heroine)
3. noun

   a muscle that contracts while another relaxes
   “when bending the elbow the biceps are the agonist”

   type of:

   antagonistic muscle

   (physiology) a muscle that opposes the action of another
4. noun

   (biochemistry) a drug that can combine with a receptor on a cell to produce a physiological reaction
   type of:

   drug

   a substance that is used as a medicine or narcotic