: a substance that by its chemical action can injure or kill a living thing
Word History of POISON
Both poison and potion come from the same Latin word, potio, the original meaning of which was just “a drink.” Already in Latin, however, potio could refer to a drink containing powerful substances that might heal or charm—what we call a potion. The Latin word potio became poison in Old French and began to refer to any powerful substance, whether a drink or not, that might sicken or kill when consumed. Poison and later potion both came into English from French.