pro·​to·​zo·​an | \ ˌprō-tə-ˈzō-ən How to pronounce protozoan (audio) \

Definition of protozoan

: any of a phylum or subkingdom (Protozoa) of chiefly motile and heterotrophic unicellular protists (such as amoebas, trypanosomes, sporozoans, and paramecia) that are represented in almost every kind of habitat and include some pathogenic parasites of humans and domestic animals

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Other Words from protozoan

protozoan adjective

Examples of protozoan in a Sentence

Recent Examples on the Web

The rest belong to micro-organisms — bacteria, fungi, protozoans and viruses — that are on and inside you. Fortune, "Why Washing Your Hands Too Much Could Make You Sick," 12 June 2018 The National Parasite Collection, which includes millions of specimens of lice, mites, nematodes, protozoans, ticks and other critters, arrived from the Agriculture Department in 2014. Daniel Nasaw, WSJ, "Tight at the Museum: A Smithsonian Struggles to Find Space for the World’s Stuff," 7 June 2018 Researchers also discovered that mitochondria were shared not only by all animals but also by plants, fungi, and protozoans — one of the main branches of life, known as eukaryotes. Carl Zimmer, STAT, "Shot through with microbes: How our bodies adapt to a hidden world of bacteria," 30 May 2018 While taking care of bacteria and protozoa are nice, the smaller viruses will quickly ruin your dream vacation. Ashlea Halpern, Slate Magazine, "The Best Travel Gifts," 8 Dec. 2017 Flies Many species feed on decaying organic matter and waste and have been responsible for transmission of bacterial and protozoan pathogens including: E. coli and salmonella. Kurt Snibbe, Orange County Register, "Bad bugs to watch out for in Southern California," 27 Apr. 2017 The rabbit was tested and treated for a protozoan infection. Andy Newman, New York Times, "The Doctor Will See Your Iguana Now," 12 May 2017 A lot of alarming things can be found in bed bugs; over 45 different potential human disease agents are known, including bacteria, viruses (Hepatitis B), worms, and protozoans (like the trypanosomes in the new paper). Gwen Pearson, WIRED, "Bed Bugs Won’t Give You Chagas Disease (probably)," 18 Nov. 2014

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'protozoan.' 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 protozoan

circa 1864, in the meaning defined above

History and Etymology for protozoan

New Latin Protozoa, from prot- + -zoa

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Time Traveler for protozoan

The first known use of protozoan was circa 1864

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More Definitions for protozoan



English Language Learners Definition of protozoan

: a tiny organism whose body is a single cell


pro·​to·​zo·​an | \ ˌprō-tə-ˈzō-ən How to pronounce protozoan (audio) \

Kids Definition of protozoan

: a single-celled organism (as an amoeba or paramecium) that is a protist and is capable of movement


pro·​to·​zo·​an | \ -ˈzō-ən How to pronounce protozoan (audio) \

Medical Definition of protozoan

 (Entry 1 of 2)

: any protist of the phylum or subkingdom Protozoa



Medical Definition of protozoan (Entry 2 of 2)

: of or relating to the phylum or subkingdom Protozoa

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Rhyming Dictionary: Words that rhyme with protozoan

Spanish Central: Translation of protozoan

Nglish: Translation of protozoan for Spanish Speakers Encyclopedia article about protozoan

Comments on protozoan

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


to shake or wave menacingly

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