counteract

verb

coun·​ter·​act ˌkau̇n-tər-ˈakt 

counteracted; counteracting; counteracts

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

ˌkau̇n-tər-ˈak-shən 

noun

counteractive

ˌkau̇n-tər-ˈak-tiv 

adjective

Synonyms of counteract

• offset
• neutralize
• correct

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

The Birmingham study also explored new ground, and few studies have tested whether nutrients can help counteract the vascular strain caused by prolonged sitting. —Deirdre Bardolf, FOXNews.com, 29 Nov. 2025

To counteract overstimulation and get sensory rest, Dalton-Smith recommends closing your eyes momentarily, using noise-canceling headphones, or, if possible, spending a few minutes alone in a dark, quiet room. —Ruchika T. Malhotra, CNBC, 26 Nov. 2025

And, for some families, counteracting that message begins at home. —Rheana Murray, The Atlantic, 26 Nov. 2025

The report finds brands making price changes, shifting sourcing, and improving efficiency in a bid to counteract the impact of tariffs. —Nick Lichtenberg, Fortune, 24 Nov. 2025

Word History

First Known Use

1655, in the meaning defined above

Rhymes for counteract

• artefact
• artifact
• inexact
• interact
• noncontact
• reenact
• subcontract
• abstract
• attacked
• attract
• contact
• contract

Kids Definition

counteract

verb

coun·​ter·​act ˌkau̇nt-ə-ˈrakt 

: to lessen the force, action, or influence of : offset

a drug that counteracts a poison

counteraction

-ˈrak-shən 

noun

Medical Definition

counteract

transitive verb

coun·​ter·​act ˌkau̇nt-ə-ˈrakt 

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

vitamin K counteracts the effects of warfarin

counteraction

-ˈrak-shən 

noun