Skip to main content
Select Source:

leech

leech, predacious or parasitic annelid worm of the class Hirudinea, characterized by a cylindrical or slightly flattened body with suckers at either end for attaching to prey. The leech, like other annelids, is segmented, but its numerous surface folds obscure the internal segments. In many forms the mouth has three small jaws equipped with sharp teeth. The digestive tract has lateral pouches that hold enough of the leech's staple food, blood, to last for months. The reproductive system is complex; leeches are hermaphroditic and cross-fertilizing. Nearly all leeches are aquatic, abounding in freshwater ponds in temperate regions, but they also are found in the tropics, in polar oceans, and in deserts. Some are permanent parasites of humans, horses, cattle, fish, and mollusks, but most are merely predatory. The salivary secretions of the leech contain hirudin, an anticoagulant, and other substances that promote blood flow. The medicinal leech (Hirudo medicinalis), a European freshwater leech once used by physicians to bleed patients suffering from almost any ailment, are now used to remove pooled blood from under skin grafts and other reconstructive surgeries, to treat bruises (such as black eyes), and to treat some osteoarthritis. Certain small leeches of the E Mediterranean region may enter the bodies of humans and animals through drinking water and lodge as parasites in the mouth or the respiratory passages. The giant Amazon leech can grow as large as the forearm of an adult human being. Leeches are classified in the phylum Annelida, class Hirudinea.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leech." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. 18 Feb. 2018 <http://www.encyclopedia.com>.

"leech." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (February 18, 2018). http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/leech

"leech." The Columbia Encyclopedia, 6th ed.. . Retrieved February 18, 2018 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/leech

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leech

leech1 / ch/ • n. 1. an aquatic or terrestrial annelid (class Hirudinea) with suckers at both ends. Many species are bloodsucking parasites, esp. of vertebrates, and others are predators. 2. a person who extorts profit from or sponges on others. • v. [intr.] habitually exploit or rely on: he's leeching off the abilities of others. leech2 • n. archaic a doctor or healer. leech3 • n. Sailing the after or leeward edge of a fore-and-aft sail, the leeward edge of a spinnaker, or a vertical edge of a square sail.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leech." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. 18 Feb. 2018 <http://www.encyclopedia.com>.

"leech." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. (February 18, 2018). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leech-2

"leech." The Oxford Pocket Dictionary of Current English. . Retrieved February 18, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leech-2

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leech

leech (leech) n. a type of worm that possesses suckers at both ends of its body. Certain parasitic species suck blood from animals and humans, causing irritation and, occasionally, infection. Formerly widely used for bloodletting, the medicinal leech (Hirudo medicinalis) may now be used following microsurgery to restore patency to blocked or collapsed blood vessels.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leech." A Dictionary of Nursing. . Encyclopedia.com. 18 Feb. 2018 <http://www.encyclopedia.com>.

"leech." A Dictionary of Nursing. . Encyclopedia.com. (February 18, 2018). http://www.encyclopedia.com/caregiving/dictionaries-thesauruses-pictures-and-press-releases/leech

"leech." A Dictionary of Nursing. . Retrieved February 18, 2018 from Encyclopedia.com: http://www.encyclopedia.com/caregiving/dictionaries-thesauruses-pictures-and-press-releases/leech

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leech

leech2 an aquatic or terrestrial annelid worm with suckers at both ends. Many species are bloodsucking parasites, especially of vertebrates (leeches were traditionally used in medicine to draw off blood) and others are predators, giving rise to the transferred sense of a person who extorts profit from or sponges on others (see also horseleech).

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leech." The Oxford Dictionary of Phrase and Fable. . Encyclopedia.com. 18 Feb. 2018 <http://www.encyclopedia.com>.

"leech." The Oxford Dictionary of Phrase and Fable. . Encyclopedia.com. (February 18, 2018). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leech-0

"leech." The Oxford Dictionary of Phrase and Fable. . Retrieved February 18, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leech-0

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leech

leech Any of numerous species of freshwater, marine and terrestrial annelids found in tropical and temperate regions. Its tapered, ringed body is equipped with a sucking disc at each end. Many species live on the blood of animals. Length: 13–51mm (0.5–2in). Class Hirudinea.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leech." World Encyclopedia. . Encyclopedia.com. 18 Feb. 2018 <http://www.encyclopedia.com>.

"leech." World Encyclopedia. . Encyclopedia.com. (February 18, 2018). http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/leech

"leech." World Encyclopedia. . Retrieved February 18, 2018 from Encyclopedia.com: http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/leech

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leech

leech1 a term (now archaic or humorous) for a doctor or healer. Recorded from Old English, the word was later often understood as a transferred use of leech2, sometimes with an indication of rapacity.

Leechcraft is similarly used for the art of healing.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leech." The Oxford Dictionary of Phrase and Fable. . Encyclopedia.com. 18 Feb. 2018 <http://www.encyclopedia.com>.

"leech." The Oxford Dictionary of Phrase and Fable. . Encyclopedia.com. (February 18, 2018). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leech

"leech." The Oxford Dictionary of Phrase and Fable. . Retrieved February 18, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leech

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leech

leech2 blood — sucking worm, OE. lǣće (Kentish lȳċe), MDu. lake, l(i)eke; orig. a distinct word from prec. but assim. to it.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leech." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. 18 Feb. 2018 <http://www.encyclopedia.com>.

"leech." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. (February 18, 2018). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leech-4

"leech." The Concise Oxford Dictionary of English Etymology. . Retrieved February 18, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leech-4

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leech

leech3 (naut.) vertical or sloping side of a sail. XIV lich(e)). Obscurely connected with ON. (naut.) lík (cf. Sw. lik, Da. lig bolt rope).

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leech." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. 18 Feb. 2018 <http://www.encyclopedia.com>.

"leech." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. (February 18, 2018). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leech-5

"leech." The Concise Oxford Dictionary of English Etymology. . Retrieved February 18, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leech-5

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leech

leech1 (arch.) physician. OE. lǣċe = OS. lāki, OHG. lāhhi, Goth. lēkeis :- Gmc. *lǣkjaz.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leech." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. 18 Feb. 2018 <http://www.encyclopedia.com>.

"leech." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. (February 18, 2018). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leech-3

"leech." The Concise Oxford Dictionary of English Etymology. . Retrieved February 18, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leech-3

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leeches

leeches See HIRUDINEA.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leeches." A Dictionary of Zoology. . Encyclopedia.com. 18 Feb. 2018 <http://www.encyclopedia.com>.

"leeches." A Dictionary of Zoology. . Encyclopedia.com. (February 18, 2018). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/leeches

"leeches." A Dictionary of Zoology. . Retrieved February 18, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/leeches

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leech

leechbeach, beech, beseech, bleach, breach, breech, each, impeach, leach, leech, outreach, peach, pleach, preach, reach, screech, speech, teach •horseleech

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leech." Oxford Dictionary of Rhymes. . Encyclopedia.com. 18 Feb. 2018 <http://www.encyclopedia.com>.

"leech." Oxford Dictionary of Rhymes. . Encyclopedia.com. (February 18, 2018). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leech-1

"leech." Oxford Dictionary of Rhymes. . Retrieved February 18, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leech-1

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.