re·​act | \ rē-ˈakt How to pronounce react (audio) \
reacted; reacting; reacts

Definition of react

intransitive verb

1 : to exert a reciprocal or counteracting force or influence often used with on or upon
2 : to change in response to a stimulus
3 : to act in opposition to a force or influence usually used with against
4 : to move or tend in a reverse direction
5 : to undergo chemical reaction

transitive verb

: to cause to react

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Synonyms for react


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Examples of react in a Sentence

When I told her what happened, she reacted with anger. I didn't expect him to react that way. The firefighters reacted quickly when they heard the alarm. He reacted badly to the drug.
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Recent Examples on the Web The same lack of processing popped up on the second interception when Cousins didn’t react to the corner sitting in zone coverage next to his target. Andrew Krammer, Star Tribune, "Film review: Locked onto receivers, Kirk Cousins can't adjust quickly enough for Vikings," 20 Oct. 2020 That makes sense, considering that the driver of a moving vehicle may not react safely to a jump scare. Carly Mallenbaum, USA TODAY, "Halloween drive-thru: In COVID times, is a spooky car experience worth the trip?," 15 Oct. 2020 The group's lobbyist, Scott Stenger, did not immediately react to Hong's criticisms. Patrick Marley, Milwaukee Journal Sentinel, "Favorite to win Assembly seat in Madison uses C-word to describe tavern lobbyists," 14 Oct. 2020 And the Alaska Supreme Court did not react kindly to the State’s alternative argument that a warrant was unnecessary for private property seizure. David Reamer, Anchorage Daily News, "Despite the odds, Anchorage used to have 3 drive-in movie theaters in operation at the same time," 11 Oct. 2020 Pence didn't react to the fly at all and for two solid minutes the fly captivated a nation. Nick Romano,, "Stephen Colbert addresses Mike Pence's fly moment: 'He's so full of crap he's attracting flies'," 8 Oct. 2020 Wilson was signaled to start running and the Twins did not react. Patrick Reusse, Star Tribune, "1968 World Series champion Tigers had a story all their own besides beating Bob Gibson in Game 7," 3 Oct. 2020 Roman public opinion did not react badly to Nero’s foreign tour. Gaia Squarci, Smithsonian Magazine, "The New, Nicer Nero," 18 Sep. 2020 But Blake chose not to react too strongly to this shift in guidance. Eric Berger, Ars Technica, "Science and steely nerves spared Houston from a nightmare hurricane evacuation," 1 Sep. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'react.' 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 react

1644, in the meaning defined at intransitive sense 1

History and Etymology for react

New Latin reactus, past participle of reagere, from Latin re- + agere to act — more at agent

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Time Traveler for react

Time Traveler

The first known use of react was in 1644

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Statistics for react

Last Updated

25 Oct 2020

Cite this Entry

“React.” Dictionary, Merriam-Webster, Accessed 30 Oct. 2020.

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More Definitions for react


How to pronounce react (audio)

English Language Learners Definition of react

: to behave or change in a particular way when something happens, is said, etc.
of a chemical substance : to change after coming into contact with another substance
medical : to be affected by a drug, food, etc., in usually a bad way


re·​act | \ rē-ˈakt How to pronounce react (audio) \
reacted; reacting

Kids Definition of react

1 : to act or behave in response to something Firefighters reacted quickly to the situation.
2 : to oppose a force or influence
Hint: In this sense, react is usually used with against. Workers reacted against unfair treatment.
3 : to go through a chemical reaction Acids react with bases to form salt.
re·​act | \ rē-ˈakt How to pronounce react (audio) \

Medical Definition of react

1 : to respond to a stimulus
2 : to undergo chemical reaction

transitive verb

: to cause to react

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Comments on react

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