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

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

Higher rates can still lift net interest income as securities reprice at higher yields, but BNY’s institutional depositors are also quicker to demand higher rates, counteracting some of the benefit. — Alexa Lomonaco, CNBC, 25 Sep. 2026

In a unique crossover, the artists and designers all strived for softness and calm to counteract the hustle and bustle of London. — Hikmat Mohammed, ARTnews.com, 24 Sep. 2026

May Help Lower Blood Pressure Basil seeds contain potassium, which helps manage blood pressure by counteracting sodium’s effects and relaxing blood vessels. — Lindsey Desoto, HEALTH, 23 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