[ koun-ter-akt ]
/ ˌkaʊn tərˈækt /

verb (used with object)

to act in opposition to; frustrate by contrary action.

Origin of counteract

First recorded in 1670–80; counter- + act

OTHER WORDS FROM counteract Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for counteractant

  • What had Clay to offer as a counteractant, as an equal inspiration to the pride of this lusty nation?

British Dictionary definitions for counteractant

/ (ˌkaʊntərˈækt) /


(tr) to oppose, neutralize, or mitigate the effects of by contrary action; check

Derived forms of counteract

counteraction, nouncounteractive, adjectivecounteractively, adverb
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012