polychaete worm vs polychaete

polychaete worm and polychaete both are nouns.

Word	Noun	Adjective	Verb	Adverb
polychaete worm	Yes	No	No	No
polychaete	Yes	No	No	No

As nouns, polychaete worm and polychaete are synonyms defined as:

polychaete worm and polychaete: chiefly marine annelids possessing both sexes and having paired appendages (parapodia) bearing bristles

Other synonyms of polychaete worm include polychete, polychete worm.

polychaete worm (noun)	polychaete (noun)
chiefly marine annelids possessing both sexes and having paired appendages (parapodia) bearing bristles	chiefly marine annelids possessing both sexes and having paired appendages (parapodia) bearing bristles