The Collaborative International Dictionary
Waterwort
Waterwort \Wa"ter*wort`\, n. (Bot.) Any plant of the natural order Elatine[ae], consisting of two genera ( Elatine, and Bergia), mostly small annual herbs growing in the edges of ponds. Some have a peppery or acrid taste.
Wiktionary
waterwort
n. Any of the family (taxlink Elatinaceae family noshow=1) of aquatic plants.