water chestnut

noun
1.
any aquatic plant of the genus Trapa, bearing an edible, nutlike fruit, especially T. natans, of the Old World.
2.
the fruit itself.
Also called water caltrop.
Origin
1850-55
Examples from the web for water chestnut
  • water chestnut is an annual, rooted aquatic plant with a leafy rosette that floats on the surface.
  • These invading species, which include the water chestnut and zebra mussel, have had major impacts on the ecology of the estuary.
  • In the river's freshwater shallows, the first green rosettes of water chestnut leaves will reach the surface by month's end.
British Dictionary definitions for water chestnut

water chestnut

noun
1.
Also called water caltrop. a floating aquatic onagraceous plant, Trapa natans, of Asia, having four-pronged edible nutlike fruits
2.
Chinese water chestnut, a Chinese cyperaceous plant, Eleocharis tuberosa, with an edible succulent corm
3.
the corm of the Chinese water chestnut, used in Oriental cookery