• (n. pl.) One of the two principal groups of Chaetopoda. It includes those that have prominent parapodia and fascicles of setae. See Illust. under Parapodia. Found on http://thinkexist.com/dictionary/meaning/polychaeta/
The polychaeta are the bristle worms. They are a class of marine Phylum annelida with obvious segmentation. The head usually bears tentacles and palps. Found on http://www.probertencyclopaedia.com/browse/BPA.HTM