ag·o·nist | \ˈa-gə-nist \

Definition of agonist 

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

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GnRH agonists suppress ovulation and essentially induce premature menopause. Zahra Barnes, SELF, "11 Symptoms of Premenstrual Dysphoric Disorder You Shouldn’t Ignore," 6 Feb. 2018 Among people with opioid addictions, taking an opioid agonist reduces the odds of relapsing into drug use and dying from an overdose. Brian Barnett, STAT, "Jails and prisons: the unmanned front in the battle against the opioid epidemic," 2 July 2018 The partisan agonists are not wrong about the significance of the moment. Massimo Calabresi, Time, "With Justice Kennedy Gone, It's Trump's Court Now," 28 June 2018 Other chemicals, called antagonists, shut down the receptors by preventing the agonists from entering. Jonathon Keats, Discover Magazine, "Building a Better Painkiller," 11 May 2018 Buprenorphine is considered a partial agonist, that works similarly to methadone as a replacement medication. Rita Giordano,, "Opioid addiction treatment with medicine works best. Why don't more young people get it?," 11 Apr. 2018 There are also gonadotropin-releasing hormone (GnRH) agonists, which can block the production of hormones that stimulate your ovaries and keep you from having a period, Greves explains. Korin Miller, Allure, "This Is What Endometriosis Pain Feels Like — and How to Treat It," 6 Mar. 2018 Many players only train up the easily visible Quadriceps but forget the Hamstrings in the back, leading to an agonist/antagonist imbalance that results in excess strain on the weaker hamstrings., "Injury Analysis: Everything You Need to Know About Dybala’s Hamstring Injury in 1 Minute," 7 Jan. 2018 Srinivasan studies how prostheses can restore the natural push-pull balance among muscles, called an agonist-antagonist relationship, like when our bicep flexes while our tricep stretches (and vice versa). Dan Robitzski, Popular Mechanics, "To Make Better Prostheses, We Need Better Biology," 19 Dec. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'agonist.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of agonist

1658, in the meaning defined at sense 1

History and Etymology for agonist

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

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The first known use of agonist was in 1658

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ag·o·nist | \ˈag-ə-nəst \

Medical Definition of agonist 

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

More from Merriam-Webster on agonist

Nglish: Translation of agonist for Spanish Speakers Encyclopedia article about agonist

Comments on agonist

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a state of commotion or excitement

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