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

It could be counteracted by a weaker employment number, given a slowing economy generally coincides with falling yields as investors seek out safety (bond yields move inversely to prices). —Jim Cramer, CNBC, 29 Mar. 2026

The sharp rise in the Urals price will help counteract any disruption to Moscow’s oil exports from attacks on Russia’s energy infrastructure, usually claimed by Ukraine. —Hanna Ziady, CNN Money, 27 Mar. 2026

Genes to counteract iron deficiency increased because seawater has just 1 percent the iron of fresh water or soil. —David George Haskell, Big Think, 27 Mar. 2026

To counteract the losses, Steiner has sought to focus on growth. —Glenn Taylor, Sourcing Journal, 26 Mar. 2026

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