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

The 8 Best Carpet Cleaners for Tackling Pet Messes Why Are These Cleaners Harmful to Pets? Many cleaning products with these ingredients are powerful sanitizers that counteract the messes some pets leave behind, but pet owners need to balance the cleaning strength with pet safety. —Nafeesah Allen, Better Homes & Gardens, 9 Jan. 2025

Some of them have been shown to partially counteract the impact of greenhouse gases by reflecting solar radiation back into space. —Annalisa Bracco, The Conversation, 9 Jan. 2025

The State of the Fake report highlights the urgent need for innovative solutions to counteract the growing counterfeit crisis. —Cassell Ferere, Forbes, 5 Jan. 2025

Evidence suggests that approach could counteract students' anxieties. —Rebecca Redelmeier, NPR, 22 Dec. 2024

Word History

First Known Use

1655, in the meaning defined above

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