Definitions
1.NounAn edible nut (technically a fruit) of the Spanish chestnut or sweet chestnut tree (Castanea sativa); also (chiefly preceded by a descriptive word), a nut from a related shrub or tree; or a similar nut from an unrelated plant.
2.NounIn full chestnut tree: the shrub or tree that bears this nut, the Spanish chestnut or sweet chestnut (Castanea sativa); also (chiefly preceded by a descriptive word), a shrub or tree of the genus Castanea.
3.NounWood of a chestnut tree.
4.NounShort for horse chestnut (“any of several tree species of the genus Aesculus, especially Aesculus hippocastanum; the fruit of such a tree”).
5.NounThings resembling a chestnut fruit in appearance or colour.
A dark, reddish-brown colour, like that of chestnut fruit (noun sense 1)."chestnut: "
6.NounA dark, reddish-brown colour, like that of chestnut fruit (noun sense 1)."chestnut: "
7.NounA horse with a reddish-brown coat, mane and tail.
8.NounAn oval or round horny plate located on the inner side of the leg of a horse or other equines, which is thought by some people to correspond with the thumbnail of other animals.
9.NounChiefly in old chestnut: a joke, meme, phrase, ploy, etc. which has been repeated so often as to have grown ineffective or tiresome; a cliché.
10.AdjectiveOf a deep reddish-brown colour, like that of a chestnut fruit (noun sense 1)."chestnut hair"