leech vs class Hirudinea

leech and class Hirudinea both are nouns.

Word	Noun	Adjective	Verb	Adverb
leech	Yes	No	Yes	No
class Hirudinea	Yes	No	No	No

leech (noun)	class Hirudinea (noun)
carnivorous or bloodsucking aquatic or terrestrial worms typically having a sucker at each end	hermaphroditic aquatic or terrestrial or parasitic annelids
a follower who hangs around a host (without benefit to the host) in hope of gain or advantage

leech (verb)	class Hirudinea (verb)
draw blood