D defs.my
Entry 1 sense Webster, 1913

Water chestnut

/wôt'-ẽr chĕs'-nŭtˌ/ · Wa·ter chest·nut · IPA
01 The fruit of Trapa natans and Trapa bicornis, Old World water plants bearing edible nutlike fruits armed with several hard and sharp points…
  1. 1.
    The fruit of Trapa natans and Trapa bicornis, Old World water plants bearing edible nutlike fruits armed with several hard and sharp points; also, the plant itself; -- called also water caltrop.(Bot.) Also: water caltrop