Source : Webster's Revised Unabridged Dictionary (1913)

Polyzoan \Pol`y*zo"an\, n. (Zo["o]l.)
   (a) Any species of Polyzoa; one of the Polyzoa.
   (b) A polyzo["o]n.

Source : WordNet®

polyzoan
     n : sessile aquatic animal forming mosslike colonies of small
         polyps each having a curved or circular ridge bearing
         tentacles; attach to stones or seaweed and reproduce by
         budding [syn: {bryozoan}, {sea mat}, {sea moss}, {moss
         animal}]
     [also: {polyzoa} (pl)]