# leech

/ˈɫitʃ/ (US) · /lˈiːtʃ/ (UK) · CEFR C2 · Noun

Source: https://englishreference.com/word/leech
Updated: 2026-05-08

## Definition

a small worm that lives in water and sucks blood from animals or people. In the past, doctors used them to treat sick people, but today the word is often used for someone who takes money or help from others without giving anything back.

For teachers: a blood-sucking annelid worm typically found in freshwater environments. Historically used for bloodletting in medicine; in modern metaphorical usage, refers to a person who parasitically exploits others.

## Examples

- The swimmer found a leech on his leg after leaving the pond.
- He realized his cousin was a leech who only called when he needed to borrow money for rent.
- While modern medicine has largely moved past bloodletting, surgeons occasionally use a medicinal leech to stimulate circulation in reattached tissue or skin grafts where blood flow is restricted.

## Usage notes

- When used metaphorically for a person, it carries a strong negative connotation of exploitation.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.