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

• annul
• cancel (out)
• compensate (for)
• correct
• counterbalance
• counterpoise
• make up (for)
• negative
• neutralize
• offset

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

Harris is already considering making some changes in an attempt to counteract the prowess of the career Grand Slam winner and a select group of other pros who can bomb it into oblivion. —Gabby Herzig, New York Times, 13 May 2025

To counteract this, don’t wait for someone else to step in — take the lead and reach out yourself. —Mark Travers, Forbes.com, 8 May 2025

Instead, the church has responded by doubling its efforts and focusing on Christian ways to counteract these cruel measures. —Chicago Tribune, 8 May 2025

In addition, the movement helps counteract climate change by improving carbon sequestration in the soil. —Matt Rozo, Mercury News, 7 May 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