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[ree-ey-juh nt] /riˈeɪ dʒənt/
noun, Chemistry.
a substance that, because of the reactions it causes, is used in analysis and synthesis.
Origin of reagent
1790-1800; re(act) + agent; cf. act Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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British Dictionary definitions for reagent


a substance for use in a chemical reaction, esp for use in chemical synthesis and analysis
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for reagent

1785, from re- + agent "substance that produces a chemical reaction."

Online Etymology Dictionary, © 2010 Douglas Harper
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reagent in Medicine

reagent re·a·gent (rē-ā'jənt)
A substance used in a chemical reaction to detect, measure, examine, or produce other substances.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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reagent in Science
A substance participating in a chemical reaction, especially one used to detect, measure, or produce another substance. Compare agent.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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