reactant

[ ree-ak-tuh nt ]
/ riˈæk tənt /

noun

a person or thing that reacts.
Also called interactant. Chemistry. any substance that undergoes a chemical change in a given reaction.

Origin of reactant

First recorded in 1925–30; react + -ant
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for reactant

British Dictionary definitions for reactant

reactant

/ (rɪˈæktənt) /

noun

a substance that participates in a chemical reaction, esp a substance that is present at the start of the reactionCompare product (def. 4)
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

Medicine definitions for reactant

reactant

[ rē-ăktənt ]

n.

A substance participating in a chemical reaction, especially a directly reacting substance present at the start of the reaction.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for reactant

reactant

[ rē-ăktənt ]

A substance participating in a chemical reaction, especially one present at the start of the reaction.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.