Naiadaceae

from The Century Dictionary.

• noun An order of monocotyledonous water-plants, of the series Apocarpeæ, typified by the genus Naias, and characterized by a free ovary without envelops or with a herbaceous perianth, usually of two or four segments.

from the GNU version of the Collaborative International Dictionary of English.

• proper noun A monotypic family of aquatic plants having narrow leaves and small flowers.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun monotypic family of aquatic plants having narrow leaves and small flowers