1. a person engaged in a contest, conflict, struggle, etc., especially the protagonist in a literary work.
  2. a person who is torn by inner conflict.
  3. Physiology. a contracting muscle whose action is opposed by another muscle.Compare antagonist(def 3).
  4. Pharmacology. a chemical substance capable of activating a receptor to induce a full or partial pharmacological response.Compare antagonist(def 5).

Origin of agonist

1620–30; < Late Latin agōnista < Greek agōnistḗs contestant, equivalent to agṓn agon + -istēs -ist Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for agonist

Historical Examples of agonist

British Dictionary definitions for agonist


  1. any muscle that is opposed in action by another muscleCompare antagonist (def. 2)
  2. a competitor, as in an agon

Word Origin for agonist

C17: from Greek agōn agon
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for agonist

1876, in writings on Greek drama, from Greek agonistes, literally "combatant in the games" (see agony).

Online Etymology Dictionary, © 2010 Douglas Harper

agonist in Medicine


  1. A contracting muscle that is resisted or counteracted by an antagonistic muscle.
  2. A substance that can combine with a cell receptor to produce a reaction typical for that substance.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

agonist in Science


  1. A muscle that actively contracts to produce a desired movement.
  2. A chemical substance, especially a drug, that can combine with a receptor on a cell to produce a physiologic response. Compare antagonist.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.