- black locust - strong stiff wood of a black-locust tree; very resistant to decay
--1 is a kind of wood
--1 is a substance of black locust, yellow locust, Robinia pseudoacacia- black locust, yellow locust, Robinia pseudoacacia - large thorny tree of eastern and central United States having pinnately compound leaves and drooping racemes of white flowers; widely naturalized in many varieties in temperate regions
--2 is a kind of locust tree, locust
--2 is a member of Robinia, genus Robinia
--2 has substances: black locust - black locust, yellow locust, Robinia pseudoacacia - large thorny tree of eastern and central United States having pinnately compound leaves and drooping racemes of white flowers; widely naturalized in many varieties in temperate regions