a tall North American tree, Gymnocladus dioica, of the legume family, the seeds of which (Kentucky coffee beans) were formerly used as a substitute for coffee beans.
Origin
1775-85
British Dictionary definitions for Kentucky coffee tree
Kentucky coffee tree
noun
1.
a North American leguminous tree, Gymnocladus dioica, whose seeds, in brown curved pulpy pods, were formerly used as a coffee substitute