leech vs horseleech

leech and horseleech both are nouns.

Word	Noun	Adjective	Verb	Adverb
leech	Yes	No	Yes	No
horseleech	Yes	No	No	No

As nouns, horseleech is a hyponym of leech; that is, horseleech is a word with a more specific, narrower meaning than leech:

leech: carnivorous or bloodsucking aquatic or terrestrial worms typically having a sucker at each end
horseleech: any of several large freshwater leeches

Other hyponyms of leech include Hirudo medicinalis, medicinal leech.

leech (noun)	horseleech (noun)
carnivorous or bloodsucking aquatic or terrestrial worms typically having a sucker at each end	any of several large freshwater leeches
a follower who hangs around a host (without benefit to the host) in hope of gain or advantage

leech (verb)	horseleech (verb)
draw blood