coun·ter·act | \ˌkau̇n-tər-ˈakt \
counteracted; counteracting; counteracts

Definition of counteract 

transitive verb

: to make ineffective or restrain or neutralize the usually ill effects of by means of an opposite force, action, or influence a drug used to counteract fatigue

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Other Words from counteract

counteraction \ˌkau̇n-tər-ˈak-shən \ noun
counteractive \ˌkau̇n-tər-ˈak-tiv \ adjective

Examples of counteract in a Sentence

The drug will counteract the poison. this medication will counteract the symptoms but it won't kill the infection

Recent Examples on the Web

In principle, this regulation provides protection against, and counteracts the effects of, the extra-territorial application of any law, such as secondary sanctions reimposed by the U.S. related to Iran. Tom Keatinge, Time, "Another Death Knell for the Iran Nuclear Deal," 4 July 2018 Finally, a third approach, being pursued by federal agencies, is whether certain drugs could help keep overdose victims breathing, without directly counteracting the opioids’ effects. Max Blau, STAT, "The next naloxone? Companies, academics search for better overdose-reversal drugs," 10 Apr. 2018 The Clooneys also previously donated $1,000,000 to the Southern Poverty Law Center to counteract hate groups, following white supremacist activity in Virginia last year. Raisa Bruner, Time, "George and Amal Clooney Just Donated $100,000 to Help Immigrant Children," 20 June 2018 The researchers also presented a number of possible tactics to counteract travel’s wear and tear on the body and mind. Sy Mukherjee, Fortune, "All That Business Travel May Be Making You Physically and Mentally Sick, Study Says," 15 June 2018 Some scientists speculate that seeding such sulfur aerosols — absent fiery eruptions — could someday be a Hail Mary to counteract climate change. Nathaniel Scharping, Discover Magazine, "Should We Cool Earth?," 18 May 2018 Walker hopes people will use NoiseScore as a tool to counteract excessive noise. Chris Berdik,, "Is Boston getting noisier? This app is designed to help us find out," 15 May 2018 Where the tax rate stands now The library implemented a 1-mill property tax for the first time in 2009 to counteract cuts from the state. Scott Wartman,, "What is Hamilton County Issue 3? The library tax levy," 10 Apr. 2018 While the Chinese economy is hardly impervious to American pressure, the much larger economic role of the state gives President Xi Jinping more levers with which to counteract the negative impact of U.S. tariffs. Jonah Shepp, Daily Intelligencer, "Trump Doubles Down on a Trade War He Can’t Win," 6 Apr. 2018

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

1655, in the meaning defined above

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Statistics for counteract

Last Updated

19 Oct 2018

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Time Traveler for counteract

The first known use of counteract was in 1655

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More Definitions for counteract



English Language Learners Definition of counteract

: act against (something) : to cause (something) to have less of an effect or to have no effect at all


coun·ter·act | \ˌkau̇n-tər-ˈakt \
counteracted; counteracting

Kids Definition of counteract

: to make (something) have less of an effect or no effect at all The antidote counteracts the poison.


transitive verb
coun·ter·act | \ˌkau̇nt-ə-ˈrakt \

Medical Definition of counteract 

: to make ineffective or restrain or neutralize the usually ill effects of by an opposite force vitamin K counteracts the effects of warfarin

Other Words from counteract

counteraction \-ˈrak-shən \ noun

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Comments on counteract

What made you want to look up counteract? Please tell us where you read or heard it (including the quote, if possible).


lying above or upon

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