The term 'counteractant' is used to describe a substance or action that can counteract or neutralize the effects of something else. In this case, the crossword solutions for the term are 'CURE' and 'ANTIDOTE'. A CURE is a remedy that can restore health or end an illness, while an ANTIDOTE is a substance that can counteract a form of poisoning or other harmful effect. Both terms refer to substances or actions that can counteract the effects of something else.