atropine
at.ro.pine \'a-tr*-.pe-n, -pe-n\ n [G atropin, fr. NL Atropa, genus name of belladonna, fr. Gk Atro]pos : a poisonous white crystalline alkaloid C17H23NO3 from belladonna and related plants used esp. to relieve spasms and to dilate the pupil of the eye