A medicine or treatment believed to protect against, counteract the effects of, or expel from the body a noxious or toxic substance, especially a poison or venom; an antidote; (in later use) especially a remedy for snakebite.
That acts as an alexipharmic; of or relating to the action of an alexipharmic.
Early 17th century; earliest use found in John Woodall (1570–1643), surgeon. Alteration of alexipharmac (by suffix substitution), after e.g. diuretic, diuretic).