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

Bent-Over Rear Delt Fly Bent-over rear delt flys strengthen the back of your shoulders, helping support good posture and counteract the effects of prolonged sitting or screen time. — Jakob Roze, HEALTH, 3 Nov. 2026

Deep wood tones counteract the cold, hard feel of modern stainless steel appliances, tile, and stone countertops, creating an inviting space. — Timothy Dale, The Spruce, 3 Nov. 2026

Potassium also helps regulate blood pressure by counteracting the effects of sodium. — Ayesha Gulzar, Verywell Health, 2 Nov. 2026

This can help counteract room acoustics that impact the sound that reaches you. — Mark Knapp, PC Magazine, 30 Oct. 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