reaction

noun
re·​ac·​tion | \ rē-ˈak-shən How to pronounce reaction (audio) \

Definition of reaction

1a : the act or process or an instance of reacting
b : resistance or opposition to a force, influence, or movement especially : tendency toward a former and usually outmoded political or social order or policy
2 : a response to some treatment, situation, or stimulus her stunned reaction to the news also : such a response expressed verbally critical reaction to the play
3 : bodily response to or activity aroused by a stimulus:
a : an action induced by vital resistance to another action especially : the response of tissues to a foreign substance (such as an antigen or infectious agent)
b : depression or exhaustion due to excessive exertion or stimulation
c : heightened activity and overaction succeeding depression or shock
d : a mental or emotional disorder forming an individual's response to his or her life situation
4 : the force that a body subjected to the action of a force from another body exerts in the opposite direction
5a(1) : chemical transformation or change : the interaction of chemical entities
(2) : the state resulting from such a reaction
b : a process involving change in atomic nuclei

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Synonyms for reaction

Synonyms

answer, reply, response, take

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Examples of reaction in a Sentence

Their reaction to the news was positive. When I told him what happened, his immediate reaction was one of shock. The announcement produced an angry reaction from most of the people at the meeting. My first reaction when I met him was not to trust him. There hasn't yet been much reaction to the announcement. There has been strong reaction against the government's policies. A good driver has quick reactions. The speed of his reactions saved his life.
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Recent Examples on the Web

But after a court filing in April mentioned the documents in suggesting that Republican leaders had made false statements to the federal court, their reaction was electric. Michael Wines, New York Times, "Deceased Strategist’s Files Detail Republican Gerrymandering in North Carolina, Advocates Say," 6 June 2019 Her reactions upon being committed to the mental institution instead of Elwood are priceless. Tom Titus, latimes.com, "On Theater: ‘Harvey’ hardly looks his age in Laguna," 6 June 2019 Steve Kerr apologized to Lowry on Thursday, while Draymond Green also condemned Stevens’s actions, and praised Lowry for his measured reaction. Rohan Nadkarni, SI.com, "Is a One-Year Ban Enough for the Warriors' Part-Owner Who Shoved Kyle Lowry?," 6 June 2019 Vargas said Buehler likely took issue with his reaction to a 2-2 curveball that Vargas took for a ball. Richard Morin, azcentral, "With eight more selections, Diamondbacks play it straight on second day of MLB draft," 4 June 2019 Many others in the trail community echoed her reaction. Stephanie Case, Outside Online, "A Response from a Proud “Lazy Parasite” Trail Runner," 4 June 2019 Many, many fans noticed what was happening and took to Twitter to express their reactions. Megan Stein, Country Living, "‘The Voice’ Got Called Out for Not Airing the Finale Performances Live," 22 May 2019 Justice and Kathryn also shared their first reactions to the movie's trailer. Gabe Bergado, Teen Vogue, ""Pokémon Detective Pikachu" Stars Justice Smith and Kathryn Newton Review Pokémon Memes," 8 May 2019 Miley seemed entertained by the whole situation, first recording her husband's silly antics and then posting her reaction on Instagram and Twitter. Katherine J. Igoe, Marie Claire, "Liam Hemsworth Fake-Trolled Wife Miley Cyrus in the Most Adorable Way," 5 May 2019

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

1585, in the meaning defined at sense 1a

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Statistics for reaction

Last Updated

13 Jun 2019

Look-up Popularity

Time Traveler for reaction

The first known use of reaction was in 1585

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More Definitions for reaction

reaction

noun

English Language Learners Definition of reaction

: the way someone acts or feels in response to something that happens, is said, etc.
: an action or attitude that shows disagreement with or disapproval of someone or something
: the ability to act and move quickly in order to avoid sudden danger

reaction

noun
re·​ac·​tion | \ rē-ˈak-shən How to pronounce reaction (audio) \

Kids Definition of reaction

1 : behavior or attitude in response to something What was your reaction to the news?
2 : a response of the body to a stimulus He had an allergic reaction to peanuts.
3 : a chemical change that is brought about by the action of one substance on another and results in a new substance being formed

reaction

noun
re·​ac·​tion | \ rē-ˈak-shən How to pronounce reaction (audio) \

Medical Definition of reaction

1 : the act or process or an instance of reacting
2 : bodily response to or activity aroused by a stimulus:
a : an action induced by vital resistance to another action especially : the response of tissues to a foreign substance (as an antigen or infectious agent)
b : depression or exhaustion due to excessive exertion or stimulation
c : abnormally heightened activity succeeding depression or shock
d : a mental or emotional disorder forming an individual's response to his or her life situation
3 : the force that a body subjected to the action of a force from another body exerts in the opposite direction
4a(1) : chemical transformation or change : the interaction of chemical entities
(2) : the state resulting from such a reaction
b : a process involving change in atomic nuclei

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Comments on reaction

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