Calabar \Cal"a*bar\, n. A district on the west coast of Africa. {Calabar bean}, The of a climbing legumious plant ({Physostigma venenosum}), a native of tropical Africa. It is highly poisonous. It is used to produce contraction of the pupil of the eye; also in tetanus, neuralgia, and rheumatic diseases; -- called also {ordeal bean}, being used by the negroes in trials for witchcraft.