duckweed definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
any of a family (Lemnaceae, order Arales) of monocotyledonous, minute flowering plants that float on ponds and sluggish streams and reproduce by a kind of budding: so called because eaten by ducks
duckweed definition by American Heritage Dictionary
Any of various small, free-floating, stemless aquatic flowering plants of the genus Lemna, growing in close, often carpetlike colonies on the surface of quiet water.