reaction
noun
re·ac·tion
| \ rē-ˈak-shən
\
\
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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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
The demonstrations grew to be a reaction to general concerns about the rights of Hong Kong residents. — Fox News, "Hong Kong police arrest at least 3 pro-democracy activists," 30 Aug. 2019 After the decision was read, there was no visible reaction from the two, who looked on solemnly. — Washington Post, "Thai Court upholds death for 2 Burmese in British murders," 29 Aug. 2019 Below are several artists' reactions to their CMA Awards nominations. — Annie Reuter, Billboard, "Carrie Underwood, Lady Antebellum & More React to 2019 CMA Nominations: 'What a Way to Start the Day!'," 28 Aug. 2019 What’s shocking, but shouldn’t be, has been the reaction of some fans and media heathens. — Paul Daugherty, Cincinnati.com, "Doc's Morning Line: Andrew Luck made a lifestyle choice. Respect it, football fans.," 28 Aug. 2019 That was the instant reaction from a friend and Crimson Tide fan upon learning inside linebacker Dylan Moses had reportedly suffered a major knee injury and could miss the entire season. — George Schroeder, USA TODAY, "Don't expect an Alabama falloff even with the loss of its most important player Dylan Moses," 28 Aug. 2019 That was the same reaction to Williams quitting on the Dolphins, at 27, on the eve of the 2004 training camp. — Dave Hyde, sun-sentinel.com, "Hyde: A change in sports for the better — Luck is commended, not reviled | Commentary," 25 Aug. 2019 There wasn’t much reaction to the news from teammates in the locker room. — Kareem Copeland, The Denver Post, "Former Broncos QB Case Keenum wins Redskins starting quarterback battle," 25 Aug. 2019 The shift may also be a reaction to the sheer ubiquity of surveillance in everyday Chinese life. — Adam Lashinsky, Fortune, "China’s Lax Attitude About Privacy Is Shifting – Data Sheet," 20 Aug. 2019These 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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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
See the full definition for reaction in the English Language Learners Dictionary
reaction
noun
re·ac·tion
| \ rē-ˈak-shən
\
\
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
\
\
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