walnut

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of several deciduous trees of the genus Juglans, having pinnately compound leaves and a round, sticky outer fruit wall that encloses a nutlike stone with an edible seed.
2. n. The stone or the ridged or corrugated seed of such a tree.
3. n. The hard, dark brown wood of any of these trees, used for gunstocks and in cabinetwork.

Century Dictionary and Cyclopedia

1. In the West Indies, a name often applied to the angelin or cabbage-tree, Vouacapoua Americana, from its resemblance in leaf and fruit to the English walnut. See cabbage-tree, 2, and Andira.
2. n. The fruit of the nut-bearing tree Juglans regia; also, the tree itself, or its wood. The walnut-tree is native from the Caucasus and Armenia to the mountains of northern India, and is extensively cultivated, and in some places naturalized, in temperate Europe. It grows from 40 to 60 or even 100 feet high, with a massive trunk and broad spreading top, and bears pinnate leaves with few smooth leaf lets. It produces the well-known sweet-seeded nuts of this name, in America distinguished as English walnuts. These are surrounded with a thin, brittle, and easily separated husk. The shell is thin in different degrees, or in the wild state thicker. The kernel yields some50 per cent, of oil, which is largely expressed in France and other parts of Europe, as also in Asia. That of the first pressing is used for food, like olive-oil, though ranked less highly; that of the second pressing, called fire-drawn, the cake having been submitted to boiling water, is more siccative even than linseed-oil, and hence is by some artists the most highly esteemed of all oils; it is a good lamp-oil, and is available for making soft-soap, etc. The whole fruit when quite young makes a good pickle. The shell of a large variety, called double walnut, is used in France for making purses, cases for jewelry, etc. The leaves and the hull of the fruit are used in Europe for various medicinal purposes. Walnut-wood is light, tough, and handsome, plain or with a bur; before the introduction of mahogany it was the leading cabinet-wood of Europe, and is still preferred to all other wood for gunstocks.
3. n. In the United States, frequently, same as black walnut and rock-walnut (the fruit, the tree, or its wood). See below.
4. n. In parts of New York, New England, and some other lo calities, same as hickory-nut or hickory. This is sometimes distinguished as shagbark or shell-bark walnut.

Wiktionary

1. n. A hardwood tree of the genus Juglans.
2. n. The nut of the walnut tree.
3. n. The wood of the walnut tree.
4. n. A dark brown colour, the colour of walnut wood.
5. adj. Having a dark brown colour, the colour of walnut wood.

GNU Webster's 1913

1. n. 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.

WordNet 3.0

1. n. nut of any of various walnut trees having a wrinkled two-lobed seed with a hard shell
2. n. any of various trees of the genus Juglans
3. n. hard dark-brown wood of any of various walnut trees; used especially for furniture and paneling