Meaning of “chestnut” - Learner’s Dictionary

chestnut

noun uk us /ˈtʃesnʌt/
NUT/TREE [ C ]

a nut that has a shiny, red-brown surface and is white inside, or the tree that produces these nuts:

roasted chestnuts
COLOUR [ C, U ]

a dark red-brown colour

→ See also horse chestnut

(Definition of “chestnut” from the Cambridge Learner’s Dictionary © Cambridge University Press)