leech vs annelid worm

leech and annelid worm both are nouns.

Word	Noun	Adjective	Verb	Adverb
leech	Yes	No	Yes	No
annelid worm	Yes	No	No	No

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

leech: carnivorous or bloodsucking aquatic or terrestrial worms typically having a sucker at each end
annelid worm: worms with cylindrical bodies segmented both internally and externally

Other hypernyms of leech include annelid, segmented worm.

leech (noun)	annelid worm (noun)
carnivorous or bloodsucking aquatic or terrestrial worms typically having a sucker at each end	worms with cylindrical bodies segmented both internally and externally
a follower who hangs around a host (without benefit to the host) in hope of gain or advantage

leech (verb)	annelid worm (verb)
draw blood