the GNU version of the Collaborative International Dictionary of English
n. A genus of the genus Daphnia.
The Century Dictionary and Cyclopedia
n. A genus of minute fresh-water cladocerous entomostracous crustaceans, the type of the family Daphniidœ, and representative of the whole order Daphniacea or Cladocera.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. minute freshwater crustacean having a round body enclosed in a transparent shell; moves about like a flea by means of hairy branched antennae
Word Usage
"In the lab, Diamond recently showed a visitor how he exposed tiny water fleas called daphnia to titanium dioxide nanoparticles."