1. any of various aquatic plants of the genus Nymphaea, species of which have large, disklike, floating leaves and showy flowers, esp. N. odorata, of America, or N. alba, of Europe. Cf. water lily family.
2. any related plant of the genus Nuphar.
3. a plant of the water lily family.
4. the flower of any such plant.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.