reagent

noun

re·​agent rē-ˈā-jənt How to pronounce reagent (audio)
: a substance used (as in detecting or measuring a component, in preparing a product, or in developing photographs) because of its chemical or biological activity

Examples of reagent in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Instead of relying on additional chemical reagents to trigger the reactions needed to capture and release metals, the researchers can use an electrical signal. — Neetika Walter, Interesting Engineering, 14 Aug. 2026 Because no agency oversees production, the conversion process leaves residual solvents, unreacted reagents, and byproducts nobody has characterized. — Jesse M. Pines, Forbes.com, 6 Aug. 2026 Radiological weapons can be detected by a Geiger counter, while chemical weapons can usually be identified by reagents, electronic sensors, and special detection sheets sensitive to things like nerve agents. — David Szondy june 27, New Atlas, 27 June 2026 Investigators used a latent bloodstain reagent and found that blood had been cleaned up from inside and outside the home, according to the affidavit. — Annasofia Scheve, San Antonio Express-News, 13 Apr. 2026 See All Example Sentences for reagent

Word History

Etymology

New Latin reagent-, reagens, present participle of reagere to react — more at react

First Known Use

1797, in the meaning defined above

Time Traveler
The first known use of reagent was in 1797

Phrases Containing reagent

Rhymes for reagent

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Browse Nearby Words

reagency
reagent
reaggregate
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Cite this Entry

“Reagent.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/reagent. Accessed 16 Aug. 2026.

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Medical Definition

reagent

noun
re·​agent rē-ˈā-jənt How to pronounce reagent (audio)
1
: a substance used (as in detecting or measuring a component, in preparing a product, or in developing photographs) because of its chemical or biological activity
2
: reactor sense 1b

More from Merriam-Webster on reagent

Britannica.com: Encyclopedia article about reagent

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