parasite

[ par-uh-sahyt ]

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:

   They are greedy politicians, parasites with their snouts in the public trough.

   Synonyms: hanger-on, sponge, leech, toady, sycophant

3. (in ancient Greece) a person who received free meals in return for amusing or impudent conversation, flattering remarks, etc.

parasite

/ ˈpærəˌsaɪt; ˌpærəˈsɪtɪk /

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

parasite

/ păr′ə-sīt′ /

1. 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 harmful to their hosts, although the damage they do ranges widely from minor inconvenience to debilitating or fatal disease.
2. ◆ 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.
3. ◆ 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.
4. See more at host

parasite

1. 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 .

Notes

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

Derived Forms

• ˌparaˈsitically, adverb
• parasitic, adjective

Word History and Origins

Origin of parasite¹

First recorded in 1530–40; from Latin parasītus, from Greek parásītos one who eats at another's table, originally an adjective: “feeding beside,” equivalent to para- + sît(os) “grain, food” + -os adjective suffix; para- ¹

Word History and Origins

Origin of parasite¹

C16: via Latin from Greek parasitos one who lives at another's expense, from para- ¹+ sitos grain

Example Sentences

Now, new research on the genetic instruction book of this rare plant reveals the lengths to which it has gone to become a specialized parasite.

From Science News

Scientific findings reported this year that still need more proof include potential signs of life on Venus and Earth’s oldest parasites.

From Science News

Ditching energy-expensive traits, or “reductive evolution,” is a common theme in parasites, Meyer noted.

From Quanta Magazine

Pandas are known to cover themselves in natural scents, which may ward off parasites or act as a territorial signal.

From Science News

During Africa’s dry season, when mosquitoes are scarce, malaria parasites have a hard time spreading to new hosts.

From Science News

The film reaches its climax when Temple is felled by giardia, a parasite that infects the small intestine.

From The Daily Beast

It was Italian doctors who proved that the parasite was carried by mosquitoes.

From The Daily Beast

Al Qaeda is a parasite that feeds on social instability and turmoil.

From The Daily Beast

All of this feeds a caricature of Washington as a parasite on the real economy.

From The Daily Beast

A single platelet lying upon a red corpuscle may easily be mistaken for a malarial parasite (Plate VI).

From Project Gutenberg

The spirillum of relapsing fever can be identified by the method for the malarial parasite in fresh blood.

From Project Gutenberg

With the tertian parasite, the segments more frequently form an irregular cluster.

From Project Gutenberg

If a parasite does not make him laugh, he perhaps does not please him, and therefore must be dismissed.

From Project Gutenberg

If a parasite cannot exist outside animal tissues, it is an obligatory parasite; if it can, it is a facultative saphrophyte.

From Project Gutenberg