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

In the study, 10 children had parasites with genetic mutations previously associated with artemisinin partial resistance.

From Science Daily

Scientists believe that it evolved to protect human beings from invisible contaminants such as pathogens and parasites.

From Salon

After all, parasites like hematophages are the bedrock of the tree of life, outnumbering free living species by about 3 to 2.

From Salon

As the Arctic warms, polar bears face a growing risk of contracting viruses, bacteria and parasites that they were less likely to encounter just 30 years ago, research has revealed.

From BBC

Malaria is caused by a complex parasite which is spread by mosquito bites.

From BBC