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

To counteract that, the oil needs to be heated so that when the water inevitably hits it, the water will boil and evaporate right away. — Ryan Canfield, FOXNews.com, 12 Aug. 2026

These efforts to cap the wholesale acquisition cost (WAC) of the drugs counteracted the GLP-1 tailwind, resulting in a net-neutral top-line impact for Cardinal Health in the June quarter. — Zev Fima, CNBC, 11 Aug. 2026

To counteract this trend, individuals should actively seek out and appreciate challenges, avoid over-reliance on technology, and instill the value of effort in children. — Tracy Brower, Forbes.com, 10 Aug. 2026

This method will allow satellites in very low Earth orbit (VLEO) — the region from roughly 60 miles to 250 miles (100 to 400 kilometers) above our planet — to counteract atmospheric drag without the aid of liquid fuel. — Julian Dossett, Space.com, 9 Aug. 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