bloodsucker vs leech

bloodsucker and leech both are nouns.

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

As nouns, bloodsucker and leech are synonyms defined as:

bloodsucker and leech: carnivorous or bloodsucking aquatic or terrestrial worms typically having a sucker at each end

Other synonyms of bloodsucker include hirudinean.

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

bloodsucker (verb)	leech (verb)
	draw blood