Simple Definition of counteract
: act against (something) : to cause (something) to have less of an effect or to have no effect at all
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>
First Known Use of counteract
COUNTERACT Defined for Kids
Definition of counteract for Students
: to make (something) have less of an effect or no effect at all <The antidote counteracts the poison.>
Seen and Heard
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