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

Large air intakes that open up in front of the rear wheels are shaped to pull air through the car, helping counteract the area of low pressure that tends to form behind a fast moving car. Peter Valdes-dapena, CNN, "Lotus unveils a super powerful electric supercar for $2 million," 16 July 2019 Doing moves to strengthen them can help counteract some of the tension indoor cycling class can cause. Jenny Mccoy, SELF, "Are Those Push-Ups in My Indoor Cycling Class Actually Doing Anything?," 30 June 2019 Lug nuts on the right side of the car: Typical on older cars, the reverse threading is intended to counteract the initial inertia of the lug nut against the rotation of the wheels. Popular Mechanics Editors, Popular Mechanics, "15 Things My Father Taught Me," 17 June 2016 Armstrong had one option remaining, to activate the thrusters reserved for re-entry to counteract the problem. Jamie Turner,, "How Neil Armstrong earned the moon landing’s lead role: Apollo 11 at 50," 16 July 2019 In an attempt to counteract rising global inventories and shore up oil prices, OPEC and its allies agreed to extend their continuing output reduction—initially implemented late last year—for another nine months. David Hodari, WSJ, "OPEC Maintains World Oil Demand Forecast as Supply Concerns Continue," 11 July 2019 This physically shifts the sensor inside the camera in order to counteract unsteadiness from the photographer’s hands. Vlad Savov, The Verge, "Panasonic Lumix S1 review: the mirrorless heavyweight," 18 June 2019 On the surface, Etika embodied social media fame, but his actions counteracted that narrative. Jason Parham, WIRED, "Depth of Field: The Quiet Force of YouTuber Etika's Gaze," 27 June 2019 The most recent of Castro’s detailed policy papers aim tens of billions of dollars toward counteracting a housing affordability crisis while also tackling segregation issues that have festered for decades. Bill Lambrecht,, "Texan Julián Castro needs a spark tonight in first Democratic debate," 26 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

10 Aug 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).


to shake or wave menacingly

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