WordNet sense 1 (smooth-barked North American hickory with 7 to 9 leaflets bearing a hard-shelled edible nut):

mockernut, big-bud hickory, Carya tomentosa, mockernut hickory, white-heart hickory

WordNet sense 2 (an American hickory tree having bitter nuts):

pignut, brown hickory, Carya glabra, pignut hickory

WordNet sense 3 (North American walnut tree with hard dark wood and edible nut):

black walnut, black walnut tree, Juglans nigra