counteract

American  

[koun-ter-akt] / ˌkaʊn tərˈækt /

verb (used with object)

1. to act in opposition to; frustrate by contrary action.

   Synonyms:

   thwart, contravene, counterbalance, neutralize

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counteract British  

/ ˌkaʊntərˈækt /

verb

1. (tr) to oppose, neutralize, or mitigate the effects of by contrary action; check

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Other Word Forms

• counteractant adjective
• counteracter noun
• counteractingly adverb
• counteraction noun
• counteractive adjective
• counteractively adverb
• counteractor noun
• noncounteractive adjective
• uncounteracted adjective

Etymology

Origin of counteract

First recorded in 1670–80; counter- + act

Example Sentences

None of it did much to counteract the sense that life had become too expensive.

From Slate • Mar. 25, 2026

Announcing its approval, the FCC said the deal would help "counteract the growing imbalance of power" between local broadcast TV stations and the large media firms, including Fox, Disney and Paramount, that dominate programming.

From BBC • Mar. 20, 2026

The researchers evaluated whether WUSTL0717 could counteract the severe weight loss that often follows small bowel resection.

From Science Daily • Mar. 18, 2026

Those sources of uncertainty could counteract positive signs the economy was previously showing and have made projecting the rest of the fiscal year far more difficult, the company said.

From The Wall Street Journal • Mar. 3, 2026

By putting two gold-covered plates on a sensitive twist-measuring device, he determined how much force it took to counteract the Casimir force between them.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife

Related Words

• cancel out
• correct
• counterbalance
• halt
• negate
• neutralize
• offset
• prevent
• rectify
• redress
• resist
• thwart