WordNet (r) 3.0 (2006):

water-shield
    n 1: aquatic plant with floating oval leaves and purple flowers;
         in lakes and slow-moving streams; suitable for aquariums
         [syn: water-shield, Brasenia schreberi, water-target]
    2: common aquatic plant of eastern North America having floating
       and submerged leaves and white yellow-spotted flowers [syn:
       water-shield, fanwort, Cabomba caroliniana]