parasite

plural parasites

1. biologyAn organism that lives on or in another organism of a different species, deriving benefit from living on or in that other organism, while not contributing towards that other organism sufficiently to cover the cost to that other organism.

   Lice, fleas, ticks, and mites are widely spread parasites.

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   ...and the mistletoe crept round many of the oaks—that pleasant parasite, whose associations belong rather to the hearth and lighted hall than to its native branches.

   1834, L[etitia] E[lizabeth] L[andon], chapter XIX, in Francesca Carrara. […], volume III, London: Richard Bentley, […], (successor to Henry Colburn), →OCLC, page 154

   It is likely that the long evolutionary trajectory of Mycoplasma went from a reductive autotroph to oxidative heterotroph to a cell-wall–defective degenerate parasite. This evolutionary trajectory assumes the simplicity to complexity route of biogenesis, a point of view that is not universally accepted.

   2013 March 28, Harold J. Morowitz, “The Smallest Cell”, in American Scientist, volume 101, number 2, archived from the original on 04 Jan 2017, page 83

   Yiannas said there has been widespread public confusion about cyclosporiasis, an intestinal illness caused by the microscopic parasite Cyclospora cayetanensis, also known as cyclospora, that can cause explosive diarrhea.

   2026 July 25, Oliver Milman, “Former FDA official says US handling of cyclospora near ‘catastrophic level’”, in The Guardian, archived from the original on 26 Jul 2026

   1. informalspecificallybiologyAn internal parasite that is an animal or protist.

      Any germs or parasites on the surface of the meat that you could conceivably wash off are gonna die as soon as you cook it, so don't bother washing it.

      2020 November 20, Adam Ragusea, 1:13 from the start, in Why People Wash Meat (or Don't)

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      He lacks, however, even the basic Dr. Kildare lingo about medical issues. For instance, he regularly misidentifies poppers as amyl nitrate, instead of amyl nitrite — two forms of heart medicine with different affects ^([sic]). Salmonella, a bacteria, is not usually classified as a parasite. And he mistakenly writes, "lenti means slow" in the lentiviruses. ("Lenti" means lens-shaped, biologists classify by structure, not by behavior.)

      1987 December 27, Charley Shively, “AIDS In The Mind Of The Left And The Mainstream”, in Gay Community News, volume 15, number 24, page 9

      Select a disease class Virus: Fastest evolution, Most affected by environment, Bonus to infectivity Bacteria: Medium evolution, Normally affected by environment, Bonus to drug resistance Parasite: Slowest evolution, Least affected by environment, Low visibility

      2008 July 14, Dark Realm Studios, Pandemic II, Web

2. derogatoryA person who lives on other people's efforts or expense and gives little or nothing back.First known use 16th c.

   A royalist who publicly called for a military intervention to protect the parasite monarchy.

   2021 December 1, monamu98, “Thai and Korean netizens oppose debut of H1-Key's Sitala over father's alleged support of dictatorship”, in Sportskeeda, Sportskeeda, archived from the original on 03 Dec 2021, retrieved 03 Dec 2021

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   Of all the corrupting effects of wealth there is none worse than this, that it makes the wealthy (and their parasites) think in some way divine, or at least a lovely character of the mind, what is in truth nothing but their power of luxurious living.

   1902, Hilaire Belloc, The Path to Rome

   Synonyms: bloodsucker, bludger, bummer, freeloader, free rider, gadfly, leech, mooch

3. derogatoryA sycophant or hanger-on.
4. literarypoeticA climbing plant which is supported by a wall, trellis etc.First known use 19th c.

   Her golden tresses shade / The bosom's stainless pride, / Curling like tendrils of the parasite / Around a marble column.

   1813, Percy Bysshe Shelley, “Canto I”, in Queen Mab; […], London: […] P. B. Shelley, […], →OCLC, page 3

5. historicalA retainer or companion of an ancient Celtic warrior, who praised him in song or poetry at gatherings; a bard.
6. aeronauticsA component of a composite aircraft which is carried aloft and air-launched by a larger carrier aircraft or mother ship to support the primary mission of the carrier; a parasite aircraft.

   […] parasiting and aerial refueling as range-extension measures. Second, parasiting would be exorbitantly expensive, because each parasite bomber would need its own carrier. Two bombers could be serviced by a single tanker, however,[…]

   2019 January 24, Michael E. Brown, Flying Blind: The Politics of the U.S. Strategic Bomber Program, Cornell University Press, →ISBN, page 170

7. attributivebusinessAn isolated (FSDU) (freestanding display unit )

   parasite unit

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   parasite display

   parasite stand

present singular third person parasites · participle present parasiting · participle past parasited · past parasited

1. rareTo parasitize.

   ... parasiting upon her husband, taking everything and giving nothing in return, this woman had brought her husband to a condition of serious ill health because of his grief, anxiety, and despair over her failure.

   1921, Margaret J. Hamilton, Mental Hygiene and the Parasite, page 19

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   ... parasiting Google, but as is the case with Microsoft's street art advertisements, the relationship is not a stable one. Using a Google map platform to track his work means sharing his location data with the corporation.

   2021 June 8, Macs Smith, Paris and the Parasite: Noise, Health, and Politics in the Media City, MIT Press, →ISBN