chestnut

Definitions

• A tree or shrub of the genus Castanea.
• The nut of this tree or shrub.
• (uncountable) A dark, reddish-brown colour, as seen on the fruit of the chestnut tree.
• A reddish-brown horse.
• (uncountable) The wood of a chestnut tree.
• (idiomatic) An old joke; a worn-out meme, phrase, ploy, etc. so often repeated as to have grown tiresome or ineffective (often in the phrase "old chestnut").
• A round or oval horny plate found on the inner side of the leg of a horse or other animal, similar to a birthmark on a human.
• (UK) The horse-chestnut.