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
Calabar bean in American English
the large, brown, poisonous seed of a woody, leguminous tropical African vine (Physostigma venenosum) used in medicine as a source of physostigmine
Word origin
after Calabar, name of a river & town in S Nigeria