1.
a. Any of several deciduous trees of the genus Castanea native to northern temperate regions, having alternate, simple, toothed leaves, and nuts enclosed in a prickly husk. b. The often edible nut of any of these trees. c. The wood of any of these trees.
2. Any of several other plants, such as the horse chestnut.
3. Color. A moderate to deep reddish brown.
4. A reddish-brown horse.
5. A small, hard callus on the inner surface of a horse's foreleg.
6. An old, frequently repeated joke, story, or song.
Of a moderate to deep reddish brown.