Pronunciation (UK) (US) IPA (key): /ˈtʃɛs.nʌt/ or /ˈtʃɛst.nʌt/ Audio (US)(file) Audio (US)(file) Audio (AU)(file) Noun Singular chestnut Plural chestnuts (countable) A chestnut is a type of tree. (countable) A chestnut is a brown nut with a smooth hard shell that comes from the chestnut tree. He is allergic to chestnuts and peanuts. (uncountable) Chestnut is a type of color that is reddish-brown. Wikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads