counteract

1 of 2

verb

counteracted; counteracting; counteracts
Synonyms of counteractnext

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

counteraction

2 of 2

noun

plural -s
1
: contrary action : opposition, resistance
scheming counteraction
2
: act or action of counteracting : a counteracting agency
the counteraction of centripetal forces on centrifugal tendencies

Examples of counteract in a Sentence

Verb The drug will counteract the poison. this medication will counteract the symptoms but it won't kill the infection
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Verb
Four types of hyaluronic acid plump skin and counteract potential dryness, while collagen amino acids and antioxidants help protect skin’s natural collagen for a firmer, smoother look. — Christa Joanna Lee, Allure, 7 Oct. 2026 It is designed to counteract Republican redistricting in other states meant to aid the GOP in the 2026 midterm elections. — Erin Cox, Washington Post, 7 Oct. 2026 Yes, the Power Keyboard is heavier, but that extra heft is partly used to counteract the top-heavy imbalance when attached to a phone. — Kimberly Gedeon, PC Magazine, 1 Oct. 2026 Labor must modernize its financial architecture to counteract this evolution. — Chris Koras, Sportico.com, 28 Sep. 2026 See All Example Sentences for counteract

Word History

First Known Use

Verb

1655, in the meaning defined above

Time Traveler
The first known use of counteract was in 1655

Browse Nearby Words

Cite this Entry

“Counteract.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/counteract. Accessed 16 Oct. 2026.

Kids Definition

counteract

verb
: to lessen the force, action, or influence of : offset
a drug that counteracts a poison

Medical Definition

counteract

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