1) Alkaloid 2) Alkaloid of a bean 3) Alkaloid used as a myotic 4) Physostigmine 
• (n.) An alkaloid found in the Calabar bean, and the seed of Physostigma venenosum; physostigmine. It is used in ophthalmic surgery for its effect in contracting the pupil.
Es'er·ine noun [ From native name of the Calabar bean: confer French ésérine .] (Chemistry) An alkaloid found in the Calabar bean, and the seed of Physostigma venenosum ; physostigmine. It is used in ophthalmic surgery for its effect in contracting the pupil. 
Type: Term Pronunciation: es′ĕr-ēn Synonyms: physostigmine
physostigmine.