Juglans regia

Walnut Wal"nut, n. [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. valn["o]t, Dan valn["o]d. See {Nut}, and cf. {Welsh}.] (Bot.) The fruit or nut of any tree of the genus {Juglans}; also, the tree, and its timber. The seven or eight known species are all natives of the north temperate zone. [1913 Webster]

Note: In some parts of America, especially in New England, the name walnut is given to several species of hickory ({Carya}), and their fruit. [1913 Webster]

{Ash-leaved walnut}, a tree ({Juglans fraxinifolia}), native in Transcaucasia.

{Black walnut}, a North American tree ({Juglans 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 walnut}, or {European walnut}, a tree ({Juglans 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 color, 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 ({Juglans cinerea}), bearing long, oval, thick-shelled, oily nuts, commonly called {butternuts}. See {Butternut}. [1913 Webster]