(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. [ 1913 Webster ]
[くろぐわい;クログワイ, kuroguwai ; kuroguwai] (n) (1) (uk) Eleocharis kuroguwai (species of spikerush); (2) (uk) (See 大黒慈姑) Chinese water chestnut (Eleocharis dulcis var. tuberosa)