agonist

noun

ag·​o·​nist ˈa-gə-nist 

1

: one that is engaged in a struggle

2

[from antagonist]

a

: a muscle that is controlled by the action of an antagonist with which it is paired

b

: a chemical substance capable of combining with a specific receptor on a cell and initiating the same reaction or activity typically produced by the binding endogenous substance

dopaminergic agonists

compare antagonist sense 2b

Examples of agonist in a Sentence

Recent Examples on the Web

The Weill Family Foundation said the hub will also examine how GLP-1 agonists and other emerging therapeutics might affect cancer treatment. —Laya Neelakandan, CNBC, 27 Mar. 2025

This is an issue that won’t go away anytime soon, at least not until the prices of GLP-1 agonists drop. —Bruce Y. Lee, Forbes, 21 Mar. 2025

The drugs, known as GLP-1 receptor agonists, work by mimicking hormones in the gut and the brain to regulate appetite and feelings of fullness. —Carla K. Johnson, Los Angeles Times, 12 Feb. 2025

Those who support the commission’s change point to the need to differentiate between individuals with obesity who need treatment with medications like the blockbuster GLP-1 agonist drugs approved for weight loss and those who could be managed with lifestyle changes alone. —Faye Chiu, CNN, 24 Jan. 2025

Word History

Etymology

borrowed from Late Latin agōnista, borrowed from Greek agōnistḗs, from agōnízesthai "to contend, fight" + -istēs -ist entry 1 — more at agonize

First Known Use

1658, in the meaning defined at sense 1

Rhymes for agonist

• antagonist
• protagonist

Medical Definition

agonist

noun

ag·​o·​nist ˈag-ə-nəst 

1

: a muscle that on contracting is automatically checked and controlled by the opposing simultaneous contraction of another muscle

called also agonist muscle, prime mover

compare antagonist sense a, synergist sense 2

2

: a chemical substance (as a drug) capable of combining with a receptor on a cell and initiating the same reaction or activity typically produced by the binding of an endogenous substance

binding of adrenergic agonists

compare antagonist sense b