What does leech mean?
A leech is a worm that feeds on the blood or other bodily fluids of animals, either as a parasite or, in a few species, as a predator. The word also has a long medical association: leeches were once commonly used in bloodletting, and medicinal leeches may still be used in specialized procedures to improve blood flow after reconstructive surgery. In modern figurative use, a leech is a contemptible person who depends on or exploits others, while “leech off” means to obtain money, shelter, or other resources from someone in a one-sided way. The literal and figurative senses share an image of something that attaches itself to a host and takes what it needs. Although the word is no longer a common synonym for a bloodsucking person, it remains vivid and memorable in both its biological and social meanings.
A parasitic or predatory worm that feeds on the blood or body fluids of animals; also, disparagingly, a person who persistently exploits or depends on others.
"A leech was found attached to the deer, and a careless colleague who leeches off everyone else was jokingly compared to it."
The figurative sense is informal and contemptuous, especially when applied to a person who drains money, attention, or other resources from others.
To act as a parasite on another person, group, or resource, especially by taking advantage of their generosity or support.
"They accused him of leeching off the organization without contributing anything to its work."
The common modern expression is “leech off.” The verb is informal and usually carries a negative judgment.
The regular plural of the noun is “leeches.”
"Several leeches were removed from the animal's skin."
A leech can live for months without feeding, then attach itself to a host and drink blood for a single extended meal.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of leech
The English word leech comes from Old English lēce, the name for a bloodsucking worm. Old English lēce was borrowed from Proto-Germanic *līkōną, a form related to words meaning “leech” in other Germanic languages. The later development of the figurative sense—describing a person who takes advantage of others—reflects the leech's long-observed habit of attaching itself to a host and feeding from it.
Related word forms
How leech is actually used
In its literal sense, leech is used for the worm and, historically, for the medicinal practice of bloodletting. As a metaphor for a person, it is strongly disparaging; the verb phrase “leech off” is informal and usually implies unfairly exploiting another person's resources.