Calabar bean

noun
  1. the violently poisonous seed of an African climbing plant, Physostigma venenosum, of the legume family, the active principle of which is physostigmine.

Origin of Calabar bean

1875–80; named after Calabar, Nigeria
Also called ordeal bean.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for calabar bean

Calabar bean

noun
  1. the dark brown very poisonous seed of a leguminous woody climbing plant, Physostigma venenosum of tropical Africa, used as a source of the drug physostigmine
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012