In some parts of America, especially in new England, the name walnut is given to several species of hickory (Carya), and their fruit. Ash-leaved walnut, a tree (juglans fraxinifolia), native in transcaucasia. Black walnut, a North American tree (J. Nigra) valuable for its purplish brown wood, which is extensively used in cabinetwork and for gunstocks. The nuts are thick-shelled, and nearly globular. English, or European, walnut, a tree (J. Regia), native of asia from the Caucasus to japan, valuable for its timber and for its excellent nuts, which are also called madeira nuts. Walnut brown, a deep warm brown colour, like that of the heartwood of the black walnut. Walnut oil, oil extracted from walnut meats. It is used in cooking, making soap, etc. White walnut, a North American tree (J. Cinerea), bearing long, oval, thick-shelled, oily nuts, commonly called butternuts. See Butternut.
Origin: OE. Walnot, AS. Wealh-hnutu a Welsh or foreign nut, a walnut; wealh foreign, strange, n, a Welshman, Celt (akin to OHG. Walh, properly, a Celt, from the name of a Celtic tribe, in L. Volcae) _ hnutu a nut; akin to D. Walnoot, G. Walnuss, Icel. Valhnot, Sw. Valnot, Dan valnod. See Nut, and cf. Welsh.