leech vs sponger

leech and sponger both are nouns.

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

As nouns, leech and sponger are synonyms defined as:

leech and sponger: a follower who hangs around a host (without benefit to the host) in hope of gain or advantage

Other synonyms of leech include parasite, sponge.

leech (noun)	sponger (noun)
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
a follower who hangs around a host (without benefit to the host) in hope of gain or advantage	a workman employed to collect sponges

leech (verb)	sponger (verb)
draw blood