agonist

American  

[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.

4. Pharmacology. a chemical substance capable of activating a receptor to induce a full or partial pharmacological response.

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agonist British  

/ ˈæɡənɪst /

noun

1. any muscle that is opposed in action by another muscle Compare antagonist

2. a competitor, as in an agon

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agonist Scientific  

/ ăg′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.

3. Compare antagonist

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Etymology

Origin of agonist

First recorded in 1620–30; from Late Latin agōnista, from Greek agōnistḗs “contestant,” equivalent to agṓn agon + -istēs -ist

Example Sentences

If a patient’s body is already producing GLP-1 at normal or elevated levels, prescribing a long-acting agonist isn’t correcting a deficit; it may be amplifying a signal that’s already there.

From Slate • Mar. 22, 2026

Over the past year, we have spoken to scores of families whose lives have been torn apart by impulsive behaviours caused by a family of medications known as dopamine agonist drugs.

From BBC • Feb. 13, 2026

Pfizer was previously investigating an oral GLP-1 receptor agonist, but these plans stalled.

From Barron's • Feb. 3, 2026

Researchers combined survey responses about GLP-1 receptor agonist use with detailed purchase records from tens of thousands of US households.

From Science Daily • Jan. 12, 2026

Reproach she looks, about, above, Denied her light, denied her love, Denied for what she sacrificed, Doomed to be fruitless agonist.

From Helen Redeemed and Other Poems by Hewlett, Maurice Henry