bloodworm vs polychaete

bloodworm and polychaete both are nouns.

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

As nouns, polychaete is a hypernym of bloodworm; that is, polychaete is a word with a broader meaning than bloodworm:

bloodworm: a segmented marine worm with bright red body; often used for bait
polychaete: chiefly marine annelids possessing both sexes and having paired appendages (parapodia) bearing bristles

Other hypernyms of bloodworm include polychaete worm, polychete, polychete worm.

bloodworm (noun)	polychaete (noun)
a segmented marine worm with bright red body; often used for bait	chiefly marine annelids possessing both sexes and having paired appendages (parapodia) bearing bristles