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water louse

noun
  1. an aquatic isopod of the genus Asellus, common in weedy waterAlso called: water slater
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Examples from the Web for water louse

Historical Examples of water louse

  • I soon discovered the cause in the presence of a water-louse, an animal which feeds on these animalcules.