资料来源 : Webster's Revised Unabridged Dictionary (1913)

Water chestnut \Wa"ter chest"nut\ (Bot.)
   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}.

资料来源 : WordNet®

Trapa bicornis
     n : water chestnut whose spiny fruit has two rather than 4
         prongs [syn: {ling}, {ling ko}]