Noun | 1. | ![]() atropine - a poisonous crystalline alkaloid extracted from the nightshade family; used as an antispasmodic and to dilate the eye pupil; also administered in large amounts as an antidote for organophosphate nerve agents or organophosphate insecticides medicament, medication, medicinal drug, medicine - (medicine) something that treats or prevents or alleviates the symptoms of disease |