parasite

[par-uh-sahyt] /ˈpær əˌsaɪt/
noun
1.
an organism that lives on or in an organism of another species, known as the host, from the body of which it obtains nutriment.
2.
a person who receives support, advantage, or the like, from another or others without giving any useful or proper return, as one who lives on the hospitality of others.
3.
(in ancient Greece) a person who received free meals in return for amusing or impudent conversation, flattering remarks, etc.
Origin
1530-40; < Latin parasītus < Greek parásītos one who eats at another's table, orig. adj.: feeding beside, equivalent to para- para-1 + sît(os) grain, food + -os adj. suffix
Synonyms
2. sycophant, toady, leech, sponge, hanger-on.
Examples from the web for parasite
  • For the first time, the parasite that causes malaria has been observed invading the cells of a mosquito's gut.
  • Birds line their nests with parasite-resistant herbs.
  • If approved, it will be the only vaccine ever generally administered against a human parasite.
  • In the seven stages of a chigger's life, the larva stage is the only one when it is a parasite.
  • But which parasite? There are dozens, each with a different treatment.
  • The malaria parasite has a complex life-cycle.
  • Until the last century, few people on Earth were parasite-free.
  • The mere fact that one organism grows on another is not sufficient criterion for considering it to be a parasite.
  • Three years ago the company was considered a parasite and a scourge.
  • If you are the first, then you are a parasite; if the second, then you are an oasis in the desert.
British Dictionary definitions for parasite

parasite

/ˈpærəˌsaɪt/
noun
1.
an animal or plant that lives in or on another (the host) from which it obtains nourishment. The host does not benefit from the association and is often harmed by it
2.
a person who habitually lives at the expense of others; sponger
3.
(formerly) a sycophant
Derived Forms
parasitic (ˌpærəˈsɪtɪk), parasitical, adjective
parasitically, adverb
Word Origin
C16: via Latin from Greek parasitos one who lives at another's expense, from para-1 + sitos grain
Word Origin and History for parasite
n.

1530s, "a hanger-on, a toady, person who lives on others," from Middle French parasite (16c.) or directly from Latin parasitus "toady, sponger," and directly from Greek parasitos "one who lives at another's expense, person who eats at the table of another," from noun use of an adjective meaning "feeding beside," from para- "beside" (see para- (1)) + sitos "food," of unknown origin. Scientific meaning "animal or plant that lives on others" is first recorded 1640s (implied in parasitical).

parasite in Medicine

parasite par·a·site (pār'ə-sīt')
n.

  1. An organism that grows, feeds, and is sheltered on or in a different organism while contributing nothing to the survival of its host.

  2. In conjoined twins, the usually incomplete twin that derives its support from the more nearly normal fetus.

parasite in Science
parasite
  (pār'ə-sīt')   
An organism that lives on or in a different kind of organism (the host) from which it gets some or all of its nourishment. Parasites are generally harmful to their hosts, although the damage they do ranges widely from minor inconvenience to debilitating or fatal disease. ◇ A parasite that lives or feeds on the outer surface of the host's body, such as a louse, tick, or leech, is called an ectoparasite. Ectoparasites do not usually cause disease themselves although they are frequently a vector of disease, as in the case of ticks, which can transmit the organisms that cause such diseases as Rocky Mountain spotted fever and Lyme disease. ◇ A parasite that lives inside the body of its host is called an endoparasite. Endoparasites include organisms such as tapeworms, hookworms, and trypanosomes that live within the host's organs or tissues, as well as organisms such as sporozoans that invade the host's cells. See more at host.
parasite in Culture

parasite definition


An organism that lives off or in another organism, obtaining nourishment and protection while offering no benefit in return. Human parasites are often harmful to the body and can cause diseases, such as trichinosis.

Note: The term parasite is often applied to a person who takes advantage of other people and fails to offer anything in return.