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

Working as a long-acting full opioid agonist, methadone reduces opioid craving and withdrawal. —Alyssa Goldberg, USA TODAY, 13 Jan. 2025

Although this class of drugs, called GLP-1 agonists, was developed two decades ago, research into their potential uses is still in the early stages. —Juliana Kim, NPR, 21 Dec. 2024

Initially approved to manage type 2 diabetes, these GLP-1 receptor agonists gained traction in 2022 after reports of celebrity use. —Dan Perry, Newsweek, 4 Jan. 2025

For those who are overweight or obese, medications known as glucagon-like peptide-1 agonists, or GLP-1s, have become very popular as weight loss treatments. —Joshua P. Cohen, Forbes, 2 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

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