Edible nuts of any of various chestnut trees of the genus Castanea or nuts that exist in a prickly husk until autumn and then they fall to the ground as smooth moderate to deep reddish brown nuts.

Etymology: earlier chesten + "nut"; from Middle English chesteine; from Old French chastaigne, from Latin castanea; from Greek kastane, "chestnut tree"; from kastana, "sweet chestnuts".