agonist

[ag-uh-nist] /ˈæg ə nɪst/
noun
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
1620-30; < Late Latin agōnista < Greek agōnistḗs contestant, equivalent to agṓn agon + -istēs -ist
Examples from the web for agonist
  • Rescue inhalers usually contain albuterol, a short-acting beta agonist.
  • Exhale as you contract the agonist muscle and inhale as you return to start position.
British Dictionary definitions for agonist

agonist

/ˈæɡənɪst/
noun
1.
any muscle that is opposed in action by another muscle Compare antagonist (sense 2)
2.
a competitor, as in an agon
Word Origin
C17: from Greek agōnagon
Word Origin and History for agonist
n.

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

agonist in Medicine

agonist ag·o·nist (āg'ə-nĭst)
n.

  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.

agonist in Science
agonist
  (āg'ə-nĭst)   

  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.