A leech is a kind of worm that feeds by sucking blood from other animals. You might find yourself needing to pull a leech off your leg after swimming in a lake.

Because leeches are parasites, it's common for people to use the word as a metaphor for someone who sponges off of other people. If you have a friend who is always borrowing money but never pays it back, and who is known for requesting favors without granting them in return, you can call him a leech. The blood-sucking leech was once commonly used by doctors who treated patients by "bleeding" them, a practice that's still occasionally used in medicine today.

Definitions of leech

n carnivorous or bloodsucking aquatic or terrestrial worms typically having a sucker at each end

bloodsucker, hirudinean
Hirudo medicinalis, medicinal leech
large European freshwater leech formerly used for bloodletting
any of several large freshwater leeches
Type of:
annelid, annelid worm, segmented worm
worms with cylindrical bodies segmented both internally and externally

n a follower who hangs around a host (without benefit to the host) in hope of gain or advantage

parasite, sponge, sponger
Type of:
a person who accepts the leadership of another

v draw blood

bleed, phlebotomise, phlebotomize
Type of:
care for, treat
provide treatment for

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