ec·​to·​par·​a·​site ˌek-tō-ˈper-ə-ˌsīt How to pronounce ectoparasite (audio)
: a parasite that lives on the exterior of its host
ectoparasitic adjective

Examples of ectoparasite in a Sentence

Recent Examples on the Web In fact, these two mites are considered to be the most common ectoparasite of humans (d). Rebecca Kreston, Discover Magazine, 18 Apr. 2011 Paleoparasitological evidence expands the knowledge of the distribution of this ectoparasite in ancient populations. Seriously Science, Discover Magazine, 10 July 2017 Studying the ancestors of living ectoparasites, which live on the outside of their hosts, can help scientists understand how these pests evolved over millions of years into the species that live among and on us today. Brian Handwerk, Smithsonian, 10 Dec. 2019 Mature sea lice are gray, lentil-sized crustaceans, also called ectoparasites, that look like small, fanged tadpoles. Amanda Little, WIRED, 23 May 2018 All the cats had irritated, painful ears consistent with a contagious ectoparasite, the document stated. Jennifer Stockinger, Twin Cities, 23 May 2017

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'ectoparasite.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


International Scientific Vocabulary

First Known Use

1861, in the meaning defined above

Time Traveler
The first known use of ectoparasite was in 1861

Dictionary Entries Near ectoparasite

Cite this Entry

“Ectoparasite.” Dictionary, Merriam-Webster, Accessed 18 Apr. 2024.

Medical Definition


ec·​to·​par·​a·​site ˌek-tō-ˈpar-ə-ˌsīt How to pronounce ectoparasite (audio)
: a parasite that lives on the exterior of its host compare endoparasite
ectoparasitic adjective
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