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

Earlier animal trials had shown how the glucagon-like peptide 1 receptor agonist (GLP-1RA) semaglutide (Wegovy, Ozempic) drastically changed the way rats and mice sought out alcohol 'rewards' after they'd been conditioned to crave it. —New Atlas, 12 Feb. 2025

Glucagon-like peptide-1 receptor (GLP-1) agonists — which contain either semaglutide or liraglutide — are prescribed to treat type 2 diabetes and obesity, but previous studies have linked the drugs to other, unexpected benefits. —Melissa Rudy, Fox News, 23 Jan. 2025

In their study, nine patients had succumbed to potentially blinding conditions, as a result of damage to the optic nerve, while taking common GLP-1 agonist drugs such as semaglutide and tirzepatide. —New Atlas, 6 Feb. 2025

Weight-loss medications called glucagon-like peptide-1 (GLP-1) receptor agonists include Ozempic, Mounjaro, Wegovy and Zepbound—and they can be prescribed for obesity or type 2 diabetes. —Justin Gest, Newsweek, 20 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