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

• 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

Into the game was lefty reliever Anthony Banda, to counteract Barger, a pinch hitter. —Andy McCullough, New York Times, 25 Oct. 2025

But lower rates cannot easily counteract the economic uncertainty that continues to bedevil businesses or address AI’s structural impact on entry-level tech jobs. —Bryan Mena, CNN Money, 25 Oct. 2025

By engineering support layer architecture, thin-film nanocomposite membranes counteract internal concentration polarization and salt accumulation within the membrane’s porous structure, reducing the driving force for water flow. —Tejasri Gururaj, Interesting Engineering, 24 Oct. 2025

With Canna Bloom, Letizia and co-owner and founder Stephanie Lembke aimed to counteract this. —Maia Pandey, jsonline.com, 24 Oct. 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