Definition of: chestnut

(ches′nut′, -nət) noun
1. An edible nut, growing in a prickly bur.
2. Any of various trees (genus Castanea) of the beech family that bear this nut.
3. One of certain other trees: the horse chestnut.
4. A reddish-brown color; also, a horse of such a color.
5. Colloq. A worn-out joke; hence, anything trite.
6. A small, horny, wartlike callosity on the inner surface of the leg, as of a horse.
—adjective
1. Reddish-brown.
2. Made of the wood of the chestnut tree. Also ches′nut′. [ME chesten, var. of chesteine <OF chastaine <L castanea <Gk. kastanea + NUT]