an·ti·dote [ánti d?t] (plural an·ti·dotes) noun 1. substance that counteracts poison: a substance that counteracts the effects of a toxin 2. welcome relief or remedy: something that will take away or reduce the bad effects of something unpleasant or undesirable an antidote to boredom [15th century. Via Latin < Greek antidoton < antididonai "give against" < didonai "give"]