Emily Dickinson Lexicon

CHEST'NUT, n. [Sax. cystel, and the tree in Sax. is cystbeam or cystenbeam; L. castanea, the tree and the nut; Fr. chataigne; Arm. gistenen, or gestenen; W. castan; Sp. castaña; Port. castanha; It. castagna; G. kastanie; Sw. Dan. kastanie; from Welsh cast, envelopment, the root of castle, from separating, defending; so named from its shell or cover. It is often written chesnut.]

The fruit, seed or nut of a tree belonging to the genus Castanea. It is inclosed in prickly pericarp, which contains two or more seeds.