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

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

But statistics and experts caution that the uptick, which has also been recorded in secular Spain, doesn’t counteract the overall downward trend. — Nicole Winfield, Los Angeles Times, 26 Sep. 2026

But statistics and experts caution that the uptick, which has been recorded also in secular Spain, doesn't counteract the overall generational trend of children of practicing French Catholics no longer going to Mass or baptizing their babies. — CBS News, 26 Sep. 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