par·​a·​sit·​ic | \ ˌper-ə-ˈsi-tik How to pronounce parasitic (audio) , ˌpa-rə-\
variants: or less commonly parasitical \ ˌper-​ə-​ˈsi-​ti-​kəl How to pronounce parasitical (audio) , ˌpa-​rə-​ \

Definition of parasitic

1 : of, relating to, or being a parasite: such as
a(1) : living on another organism in parasitism Some caterpillars even sport white spots that resemble the eggs of the parasitic wasps that prey upon caterpillars …— Mary Parker Sonis a parasitic yeast/plant Filariasis, caused by parasitic worms in the human lymphatic system and carried in mosquitoes, infects some eighty million people in tropical and subtropical regions of the world.— Wayne Biddle
(2) : caused by or resulting from the effects of parasites a parasitic disease/infection
(3) of a bird : laying eggs in the nest of another bird The cowbird and the cuckoo are parasitic birds.
b : exploiting the hospitality of others : depending on another or others for existence or support without making a useful or adequate return … manipulated and glorified by self-serving, parasitic northern bureaucrats.— Edward Friedman
2 phonetics : of, relating to, or constituting a speech sound that is interposed between two other sounds usually as a by-product of transition from one place of articulation to another The \ə\ in \ˈeləm\ for elm or in \ˈathəˌlēt\ for athlete, the \t\ in \fents\ for fence, and the \b\ and b in \ˈnimbəl\ nimble from Middle English nimel are parasitic.

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Other Words from parasitic

parasitically \ ˌper-​ə-​ˈsi-​ti-​kəl How to pronounce parasitically (audio) , ˌpa-​rə-​ \ adverb
During sexually quiescent phase, lampreys live simply, communally or parasitically upon other fish. — Earl W. Count … those who live parasitically on the political system … — John Derbyshire

Examples of parasitic in a Sentence

Recent Examples on the Web

To environmentalists, the early grass carp invasion is a reminder of what happened with the eel-like sea lamprey, the parasitic fish responsible for crashing the native lake trout population. Tony Briscoe,, "The Great Lakes could be on the ‘edge of an invasion’ by a little-discussed species of Asian carp," 21 June 2019 If only it weren’t tainted by the corruption of a parasitic executive class. Marlo Safi, National Review, "The Beautiful, Corrupt Game," 20 June 2019 Today, Darwin’s finches are in trouble, threatened by a parasitic fly that feeds on the blood of hatchlings, sometimes causing entire nests to die. Brigit Katz, Smithsonian, "Parasites Are Ruining the Lovesongs of Darwin’s Finches," 13 June 2019 Genetic evidence suggests that this trait evolved four separate times among these lizards, which led researchers to think that the biliverdin might help protect the skinks from malaria or other parasitic infections. Quanta Magazine, "Icefish Study Adds Another Color to the Story of Blood," 22 Apr. 2019 Synthetic materials may even confer some advantages over natural ones; sparrows and finches, for instance, have been known to stuff cigarette butts into the lining of their nests as a means of warding off parasitic mites. Brigit Katz, Smithsonian, "Found: A Bees’ Nest Built Entirely of Plastic Waste," 7 June 2019 Doctors diagnosed Palma with neurocysticercosis, a parasitic infection in the brain caused by the tapeworm Taenia solium. The Washington Post,, "Surgeons opened her skull to remove a cancerous tumor. Instead, they found a tapeworm.," 6 June 2019 Doctors diagnosed Palma with neurocysticercosis, a parasitic infection in the brain caused by the tapeworm Taenia solium. The Washington Post, The Mercury News, "Doctors thought it was a tumor. It was much more gross.," 6 June 2019 In that movie, researchers in Antarctica are plagued by a parasitic being that's able to assimilate into/imitate other humans — is this a hint that some of the people in Hawkins are going to turn out to be Upside-Downers in disguise? Marisa Lascala, Good Housekeeping, "'Stranger Things 3' Promises to Be Funny, Harrowing, and Full of '80s References," 24 May 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'parasitic.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of parasitic

1630, in the meaning defined at sense 1

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Statistics for parasitic

Last Updated

28 Jun 2019

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Time Traveler for parasitic

The first known use of parasitic was in 1630

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More Definitions for parasitic



English Language Learners Definition of parasitic

of an animal or plant : living in or on another animal or plant and getting food or protection from it
: caused by a parasite
disapproving : getting food, money, etc., from other people without doing anything to earn it or deserve it


par·​a·​sit·​ic | \ ˌper-ə-ˈsi-tik\

Kids Definition of parasitic

: relating to or having the habit of a parasite : caused by parasites a parasitic worm parasitic diseases


par·​a·​sit·​ic | \ ˌpar-ə-ˈsit-ik How to pronounce parasitic (audio) \
variants: also parasitical \ -​i-​kəl How to pronounce parasitical (audio) \

Medical Definition of parasitic

 (Entry 1 of 2)

1 : relating to or having the habit of a parasite : living on another organism
2 : caused by or resulting from the effects of parasites

Other Words from parasitic

parasitically \ -​i-​k(ə-​)lē How to pronounce parasitically (audio) \ adverb



Medical Definition of parasitic (Entry 2 of 2)

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More from Merriam-Webster on parasitic

Spanish Central: Translation of parasitic

Nglish: Translation of parasitic for Spanish Speakers

Britannica English: Translation of parasitic for Arabic Speakers

Comments on parasitic

What made you want to look up parasitic? Please tell us where you read or heard it (including the quote, if possible).


to form ideas or theories about something

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