The term 'locust limb' refers to a type of tree BRANCH that is commonly found in the Midwest United States. It is characterized by its thick, gnarled bark and its ability to withstand extreme weather conditions. The term is derived from the fact that locust trees are often found in areas where there is a high concentration of locusts. The term 'BRANCH' is used to describe the part of the tree that extends out from the trunk and is typically used for support or as a source of food for animals.