[brahy-uh-zoh-uh n]
  1. Also called moss animal. any sessile marine or freshwater animal of the phylum Bryozoa, forming branching, encrusting, or gelatinous mosslike colonies of many small polyps, each having a circular or horseshoe-shaped ridge bearing ciliated tentacles, occurring on algae or on shaded objects.

Origin of bryozoan

First recorded in 1870–75; Bryozo(a) + -an Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for bryozoan


  1. any aquatic invertebrate animal of the phylum Bryozoa, forming colonies of polyps each having a ciliated feeding organ (lophophore)Popular name: sea mat
  1. of, relating to, or belonging to the Bryozoa
Popular name: polyzoan, ectoproct

Word Origin for bryozoan

C19: from Greek bruon moss + zōion animal
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

bryozoan in Science


  1. Any of various small aquatic invertebrate animals of the phylum Bryozoa that are capable of forming vast mosslike or branching colonies attached to seaweed or hard surfaces. Bryozoans reproduce by budding and feed on minute particles of plankton that they capture with tentacles. They are probably related to the phoronids and are the only animal phylum that does not appear in the fossil record until the early Ordovician Period.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.