leech

¹ American  

[leech] / litʃ /

noun

1. any bloodsucking or carnivorous aquatic or terrestrial worm of the class Hirudinea, certain freshwater species of which were formerly much used in medicine for bloodletting.

2. a person who clings to another for personal gain, especially without giving anything in return, and usually with the implication or effect of exhausting the other's resources; parasite.

   Synonyms:

   sponger, extortionist, bloodsucker

3. Archaic. an instrument used for drawing blood.

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verb (used with object)

1. to apply leeches to, so as to bleed.

2. to cling to and feed upon or drain, as a leech.

   His relatives leeched him until his entire fortune was exhausted.

3. Archaic. to cure; heal.

verb (used without object)

1. to hang on to a person in the manner of a leech.

   She leeched on to him for dear life.

leech ² American  

[leech] / litʃ /

noun

Archaic.

1. a physician.

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leech ³ American  

[leech] / litʃ /

Or leach

noun

Nautical.

1. either of the lateral edges of a square sail.

2. the after edge of a fore-and-aft sail.

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Leech ⁴ American  

[leech] / litʃ /

noun

1. Margaret, 1893–1974, U.S. historian, novelist, and biographer.

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leech ¹ British  

/ liːtʃ /

noun

1. any annelid worm of the class Hirudinea, which have a sucker at each end of the body and feed on the blood or tissues of other animals See also horseleech medicinal leech

2. a person who clings to or preys on another person

3. 1. an archaic word for physician

   2. ( in combination )

      leechcraft

4. to cling or adhere persistently to something

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verb

1. (tr) to use leeches to suck the blood of (a person), as a method of medical treatment

leech ² British  

/ liːtʃ /

noun

1. nautical the after edge of a fore-and-aft sail or either of the vertical edges of a squaresail

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Other Word Forms

• leechlike adjective

Etymology

Origin of leech¹

First recorded before 900; Middle English lech(e), Old English lǣce, lȳce; replacing (by association with leech ² ) Middle English liche, Old English lȳce; cognate with Middle Dutch lake, leke, lieke; akin to Old English lūcan “to pull up, pull out,” Middle High German liechen “to pull”

Origin of leech²

First recorded before 950; Middle English leche, lech, lecche, Old English lǣce, lēce; cognate with Old Frisian letza, leischa, Old Saxon lāki, Old High German lāhhi, Gothic lēkeis; akin to Old Norse lǣknir

Origin of leech³

First recorded in 1480–90; earlier lek, leche, lyche; akin to Dutch lijk “leech, leech line,” Old Norse līk nautical term of uncertain meaning, but probably “bolt rope, leech line”

Explanation

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.

Example Sentences

And I wanted to leech off of that.

From Los Angeles Times • Apr. 8, 2026

The decision pays off in the film’s third act, when Matthew is exonerated in the court of the public and receives the adoration he’s been trying to leech from Oliver.

From Salon • Aug. 26, 2025

They will start the leech version of running, a furious inchworming along, to try to get closer to you.

From New York Times • Jun. 20, 2024

It works according to the leech principle and is less invasive than taking blood from the arm with a needle.

From Science Daily • May 2, 2024

When she got to the other side, she scrambled up a rock and picked off a leech that had managed to fasten onto her ankle.

From "A Girl Named Disaster" by Nancy Farmer