water chestnut

(noun) a plant of the genus Trapa bearing spiny four-pronged edible nutlike fruits. Synonyms: water chestnut, water chestnut plant, caltrop.

(noun) Chinese sedge yielding edible bulb-shaped tubers. Synonyms: water chestnut, Chinese water chestnut, Eleocharis dulcis.

(noun) edible bulbous tuber of a Chinese marsh plant. Synonyms: water chestnut.