atropine

Plural: atropines

Noun

• 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
• An alkaloid extracted from the plant deadly nightshade (Atropa belladonna) and other sources, such as the seeds of the thorn-apple. Though overdoses would be fatal it is used as a drug in medicine for its paralytic effects (e.g. in surgery to relax muscles, in dentistry to dry the mouth, in ophthalmology to dilate the pupils).
• pl. -S a poisonous alkaloid