1. chestnut tree (a tree that bears chestnuts; a tree of the genus Castanea)

2. chestnut (an 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) (countable)