the large, brown, poisonous seed of a woody, leguminous tropical African vine (Physostigma venenosum) used in medicine as a source of physostigmine
after Calabar, name of a river & town in S Nigeria
See Calabar bean in American Heritage Dictionary 4
The poisonous seed of a tropical western African woody vine (Physostigma venenosum) in the pea family, which has been used as an ordeal poison and is the source of the drug physostigmine. Also called ordeal bean.
Origin: After Calabar, a town of southeast Nigeria