coun·​ter·​act | \ ˌkau̇n-tər-ˈakt How to pronounce counteract (audio) \
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 How to pronounce counteraction (audio) \ noun
counteractive \ ˌkau̇n-​tər-​ˈak-​tiv How to pronounce counteractive (audio) \ 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

However, researchers from Harvard might have found a dietary supplement that can counteract this problem: resveratrol, an antioxidant found in grape skin, blueberries and perhaps most famously, red wine. Fox News, "Red wine could help astronauts stay strong on Mars," 25 July 2019 And also looking at astronaut health, another experiment will look at how microgravity impacts healing and tissue regeneration, allowing scientists to develop better ways of counteracting bone density loss in space. Chabeli Herrera,, "SpaceX plans to launch 5,000 pounds of cargo to ISS tonight. But storms may push it to August," 24 July 2019 Chocolate Chunk Tahini Blondies Active: 25 minutes | Total: 45 minutes Servings: 24 two-inch pieces Tahini gives these blondies a nutty and faintly bitter flavor that counteracts what can otherwise be an overly sweet treat. Becky Krystal, The Denver Post, "The key to these gooey, chocolaty blondies? Open sesame.," 3 June 2019 Evidence from supernova explosions showed that the expansion is, instead, accelerating — as if there is some extra form of energy that counteracts gravity and increases the velocity of the expansion. Quanta Magazine, "An Italian Cosmologist Who Wanders in Dante’s Dark Wood," 13 Nov. 2018 Cunningham, who lives in Pasadena with his wife, Wendy, acts as a tireless booster for his adopted home, posting sparkling shots of downtown Baltimore on social media to counteract more derisive depictions of the city. Childs Walker,, "‘I realized I was done’: Bruce Cunningham steps down after 20 years as Ravens public-address announcer," 20 Aug. 2019 Launching several detectors would mitigate this problem, but Kipping notes that doing so might also counteract the cost savings that make the idea so appealing. Leila Sloman, Scientific American, "Earth Could Be a Lens for a Revolutionary Space Telescope," 14 Aug. 2019 To counteract the slumping global economy, Fed Chairman Jerome Powell has hinted that rate cuts are coming at the conclusion of the Fed's two-day policy-setting meeting Wednesday. David Goldman, CNN, "Wait, so, why is the Fed cutting rates, exactly?," 30 July 2019 In Paris, older cars are banned from the city to counteract the fact a heat wave aggravates the city’s pollution. Stephen Leahy, National Geographic, "Europe has had five 500-year summers in 15 years. And now this," 28 June 2019

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

7 Sep 2019

Look-up Popularity

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 How to pronounce counteract (audio) \
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 How to pronounce counteract (audio) \

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 How to pronounce counteraction (audio) \ 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).


concealment of treason or felony

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