chestnut a name given to many nuts, originally and primarily to those of the European ‘sweet’ or ‘Spanish’ chestnut tree, Castanea sativa, and later to various Asian and American relatives. These trees belong to regions with a temperate climate.
Chestnuts contain more starch and less oil than most other nuts and have had a special role as food for this reason. The European chestnut was formerly a staple food of great importance, but has now become more of a luxury.