Source : Webster's Revised Unabridged Dictionary (1913)

Chestnut \Chest"nut\ (ch[e^]s"n[u^]t), n. [For chesten-nut; OE.
   chestein, chesten, chastein, chestnut, fr. AS. cisten in
   cisten-be['a]m chestnut tree, influenced by OF. chastaigne,
   F. ch[^a]taigne, both the AS. and the F. words coming from L.
   castanea a chestnut, Gr. ka`stanon, fr. Ka`stana a city of
   Pontus, where chestnut trees grew in abundance, and whence
   they were introduced into Europe. Cf. {Castanets}.]
   1. (Bot.) The edible nut of a forest tree ({Castanea vesca})
      of Europe and America. Commonly two or more of the nuts
      grow in a prickly bur.

   2. The tree itself, or its light, coarse-grained timber, used
      for ornamental work, furniture, etc.

   3. A bright brown color, like that of the nut.

   4. The horse chestnut (often so used in England).

   5. One of the round, or oval, horny plates on the inner sides
      of the legs of the horse, and allied animals.

   6. An old joke or story. [Slang]

   {Chestnut tree}, a tree that bears chestnuts.