noun par·a·site \ˈper-ə-ˌsīt, ˈpa-rə-\

Definition of parasite

  1. 1 :  a person who exploits the hospitality of the rich and earns welcome by flattery sought to rid the palace of the parasites of his prosperity

  2. 2 :  an organism living in, with, or on another organism in parasitism an intestinal parasite of humans a parasite that causes malaria

  3. 3 :  something that resembles a biological parasite in dependence on something else for existence or support without making a useful or adequate return That city has become a parasite on the country.


play \ˌper-ə-ˈsi-tik, ˌpa-rə-\ or less commonly


play \-ti-kəl\ adjective


play \-ti-k(ə-)lē\ adverb

Examples of parasite in a sentence

  1. Many diseases are caused by parasites.

  2. She's a parasite who only stays with him for the money.

  3. These new companies are parasites feeding off the success of those who spent the last decade establishing the industry.

Origin and Etymology of parasite

Medieval French, from Latin parasitus, from Greek parasitos, from para- + sitos grain, food

First Known Use: 1539

Synonym Discussion of parasite

parasite, sycophant, toady, leech, sponge mean a usually obsequious flatterer or self-seeker. parasite applies to one who clings to a person of wealth, power, or influence or is useless to society a jet-setter with an entourage of parasites. sycophant adds to this a strong suggestion of fawning, flattery, or adulation a powerful prince surrounded by sycophants. toady emphasizes the servility and snobbery of the self-seeker cultivated leaders of society and became their toady. leech stresses persistence in clinging to or bleeding another for one's own advantage a leech living off his family and friends. sponge stresses the parasitic laziness, dependence, and opportunism of the cadger a shiftless sponge, always looking for a handout.

PARASITE Defined for English Language Learners


noun par·a·site \ˈper-ə-ˌsīt, ˈpa-rə-\

Definition of parasite for English Language Learners

  • : an animal or plant that lives in or on another animal or plant and gets food or protection from it

  • : a person or thing that takes something from someone or something else and does not do anything to earn it or deserve it

PARASITE Defined for Kids


noun par·a·site \ˈper-ə-ˌsīt\

Definition of parasite for Students

  1. 1 :  a living thing (as a flea, worm, or fungus) that lives in or on another living thing and gets food and sometimes shelter from it and usually causes harm to it

  2. 2 :  a person who lives at the expense of another

Medical Dictionary


noun par·a·site \ˈpar-ə-ˌsīt\

Medical Definition of parasite

  1. :  an organism living in, with, or on another organism in parasitism

Seen and Heard

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a brief usually trivial fact

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