walnut Meaning, Definition & Usage

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

WordNet

Wal"nut noun
Etymology
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. valnöt, Dan valnöd. See Nut, and cf. Welsh.
Definitions
  1. (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. ✍ In some parts of America, especially in New England, the name walnut is given to several species of hickory (Carya), and their fruit.

Webster 1913