antidote

An agent that counteracts a poison.

• chemical a. — one that neutralizes the poison by changing its chemical nature.
• mechanical a. — one that prevents absorption of the poison.
• physiological a. — one that counteracts the effects of the poison by producing opposing effects.
• universal a. — a mixture formerly recommended as an antidote when the exact poison is not known. There is, in fact, no known universal antidote. Activated charcoal is now being used for many poisons.