parasite

American  

[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.

   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.

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parasite British  

/ 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

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parasite Scientific  

/ 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

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parasite Cultural  

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.

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Discover More

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

Other Word Forms

• parasitic adjective
• parasitically adverb

Etymology

Origin of parasite

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

Compare meaning

How does parasite compare to similar and commonly confused words? Explore the most common comparisons:

• parasite vs. parasitoid

Example Sentences

The main concern centers on how veterinary parasite treatments might affect species that are not the intended targets.

From Science Daily

Wastewater typically also contains viruses, chemicals, parasites and pharmaceuticals, among other contaminants.

From The Wall Street Journal

“Vitamin C, zinc, key lime. I do my bees and my glutathione, and then I do my black walnuts because that’s a part of helping kill the parasites in the body.”

From Los Angeles Times

A parasite that may already be living in your brain has the ability to infect the very immune cells designed to eliminate it.

From Science Daily

Costs will likely stay elevated as consumer demand remains robust, while it takes years to rebuild American herds depleted by drought and import restrictions over a parasite.

From Barron's