bloodworm vs polychete worm

bloodworm and polychete worm both are nouns.

Word	Noun	Adjective	Verb	Adverb
bloodworm	Yes	No	No	No
polychete worm	Yes	No	No	No

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

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

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

bloodworm (noun)	polychete worm (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