re·act | \ rē-ˈakt \
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


reply, respond

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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 dollar fell to a three-week low Friday as investors reacted to the June employment report, which showed the economy added slightly more jobs than expected while wages increased modestly and the unemployment rate ticked higher. Orla Mccaffrey, WSJ, "Dollar Falls After June Jobs Report," 6 July 2018 As Coutinho — 26 that day — reacted in mock indignation, Neymar buckled with laughter. Rory Smith, New York Times, "All Eyes Are on Neymar, but It’s Coutinho Who Is Leading Brazil," 28 June 2018 While Microsoft has diversified its business thanks to the reach of software and its focus on the cloud, Intel has reacted more slowly. Tom Warren, The Verge, "Intel now faces a fight for its future," 22 June 2018 The three new releases have partly reacted, Reznor has said, against Donald Trump’s rise. Spencer Kornhaber, The Atlantic, "Nine Inch Nails Is Still Pushing the Sound of Catharsis," 22 June 2018 Secretary of State Mike Pompeo made the remarks at the Detroit Economic Club as global markets reacted to trade tensions between the U.S. and China. Jeff Karoub And Zeke Miller,, "Upping ante, Trump threatens new tariffs on $200 billion in Chinese imports," 19 June 2018 While press groups have criticized the seizure of Watkins’s records as a First Amendment violation, conservative outlets and Trump supporters have reacted much differently. Gabriella Paiella, The Cut, "What to Know About Ali Watkins, James Wolfe, and the FBI," 13 June 2018 Houston Mayor Sylvester Turner has reacted to that with several initiatives, including a partnership with Microsoft. Mark Collette, Houston Chronicle, "Texas has mediocre 'innovation potential,' ranking of state economies finds," 5 June 2018 The Chinese government has reacted furiously to the recent US statements. Ryan Browne, CNN, "US B52s fly by contested islands amid rising tensions with China," 4 June 2018

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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Phrases Related to react

react against

Statistics for react

Last Updated

2 Sep 2018

Look-up Popularity

Time Traveler for react

The first known use of react was in 1644

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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.

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 \
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 \

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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