- water chestnut, water chestnut plant, caltrop - a plant of the genus Trapa bearing spiny four-pronged edible nutlike fruits
--1 is a kind of aquatic plant, water plant, hydrophyte, hydrophytic plant
--1 is a member of Trapa, genus Trapa
--1 has particulars:water caltrop, Jesuits' nut, Trapa natans; ling, ling ko, Trapa bicornis