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 New technologies give rise to new challenges, and organizations react by trying to strike a balance between the advantages of new technologies and changes that employees may perceive as uncomfortable or a threat. Suresh Sambandam, Forbes, 12 Oct. 2021 Everyone is different and different bodies will react differently to certain foods. Alyssa Jung, Good Housekeeping, 3 Oct. 2021 Did supervisors react appropriately and discipline those found to be in violation of the agency’s ethical standards? ProPublica, 24 Sep. 2021 If Congress fails to lift the debt ceiling and the Treasury begins paying bills late and defaults, markets would react very negatively. Matt Egan, CNN, 22 Sep. 2021 But how could someone react like that without giving me a chance to explain? Susie Tuma Gurstein, Los Angeles Times, 18 Sep. 2021 Family members of Ty Jordan react at the unveiling of a memorial in Rice-Eccles Stadium as the Utah Utes host the Weber State Wildcats in Salt Lake City on Thursday, Sept. 2, 2021. Alex Vejar, The Salt Lake Tribune, 2 Sep. 2021 On top of those vulnerabilities, target cells may react to an outside threat—damage from a virus, for example—in ways that bring on a strong immune response. Stephani Sutherland, Scientific American, 1 Sep. 2021 The subjects are forced to react, or even re-engage with the controversy, which forms the basis for a second or third round of content. Cecilia D'anastasio, Wired, 26 Aug. 2021

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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Dictionary Entries Near react



react against

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Statistics for react

Last Updated

14 Oct 2021

Cite this Entry

“React.” Dictionary, Merriam-Webster, Accessed 26 Oct. 2021.

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More Definitions for react



English Language Learners Definition of react

: to behave or change in a particular way when something happens, is said, etc.
: to change after coming into contact with another substance
: 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.


intransitive verb
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

More from Merriam-Webster on react

Nglish: Translation of react for Spanish Speakers

Britannica English: Translation of react for Arabic Speakers


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