'Pondweed' definitions:

Definition of 'pondweed'

noun

Any of several submerged or floating freshwater perennial aquatic weeds belonging to the family Potamogetonaceae

noun

Submerged freshwater perennials [syn: Elodea, genus Elodea, pondweed, ditchmoss]

From: GCIDE

Pondweed \Pond"weed`\, n. (Bot.) Any aquatic plant of the genus Potamogeton, of which many species are found in ponds or slow-moving rivers. [1913 Webster]
Choke pondweed, an American water weed ({Anarcharis Canadensis}, syn. Elodea Canadensis.) See Anacharis.
Horned pondweed, the Zannichellia palustris, a slender, branching aquatic plant, having pointed nutlets. [1913 Webster]