dew worm vs class Oligochaeta

dew worm and class Oligochaeta both are nouns.

Word	Noun	Adjective	Verb	Adverb
dew worm	Yes	No	No	No
class Oligochaeta	Yes	No	No	No

dew worm (noun)	class Oligochaeta (noun)
terrestrial worm that burrows into and helps aerate soil; often surfaces when the ground is cool or wet; used as bait by anglers	earthworms