re·​ac·​tant | \ rē-ˈak-tənt How to pronounce reactant (audio) \

Definition of reactant

: a substance that enters into and is altered in the course of a chemical reaction

Examples of reactant in a Sentence

Recent Examples on the Web According to one study, there are actually five levels of boredom: indifferent, calibrating, searching, reactant, and apathetic. Joey Camire, Quartz, 21 Mar. 2020 For our purposes, level three (searching) and level four (reactant) are the most relevant. Joey Camire, Quartz, 21 Mar. 2020 The Chinese scientists added polyethylene glycol into the reactant mix when building their COF compound, which effectively bridged the porous spaces to create a version that was much more compact and flexible. Jennifer Ouellette, Ars Technica, 21 July 2019 Nasal swabs would be collected from a patient, placed into a tube and mixed with a reactant. Anna Bauman,, 29 Jan. 2020 Modern suits come equipped with tiny, microscopic balls of heat-reactant chemicals that helped protect astronauts from the frigid temps. Jennifer Leman, Popular Mechanics, 22 Nov. 2019 Each bubble contains its own set of reactants, which can be coalesced by driving the bubbles together. Chris Lee, Ars Technica, 26 July 2019 In this case, the researchers flow the reactants through the chamber in a single direction, and the nanotubes grow along the same direction as that flow. John Timmer, Ars Technica, 15 May 2018 This was accomplished through a variant of a standard technique called chemical vapor deposition, in which the reactants that generate the nanotube are present in the atmosphere of the reaction chamber. John Timmer, Ars Technica, 15 May 2018

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

See More

First Known Use of reactant

1916, in the meaning defined above

Learn More About reactant

Time Traveler for reactant

Time Traveler

The first known use of reactant was in 1916

See more words from the same year

Dictionary Entries Near reactant

reactance tube



See More Nearby Entries 

Statistics for reactant

Cite this Entry

“Reactant.” Dictionary, Merriam-Webster, Accessed 17 Jan. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

More Definitions for reactant



English Language Learners Definition of reactant

: a substance that changes when it is combined with another substance in a chemical reaction


re·​ac·​tant | \ -tənt How to pronounce reactant (audio) \

Medical Definition of reactant

: a substance that enters into and is altered in the course of a chemical reaction

Other Words from reactant

reactant adjective

More from Merriam-Webster on reactant Encyclopedia article about reactant


Test Your Vocabulary

Name that Thing: Flower Edition

Name That Thing

Test your visual vocabulary with our 10-question challenge!

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!