round·​worm | \ ˈrau̇nd-ˌwərm How to pronounce roundworm (audio) \

Definition of roundworm

: nematode also : a related round-bodied unsegmented worm (such as a spiny-headed worm) as distinguished from a flatworm

Examples of roundworm in a Sentence

Recent Examples on the Web Doctors in Spain diagnosed a man with an unusual roundworm infection after watching an army of larvae writhe and slither under his skin, blanketing his whole body in an ever-shifting rash. Beth Mole, Ars Technica, 22 Apr. 2022 Sadly, adding soil won’t stop root knot nematodes, a parasitic roundworm. Nan Sterman, San Diego Union-Tribune, 2 Apr. 2022 That analysis revealed the presence of parasitic eggs from four different species: whipworm, beef/pork tapeworm, roundworm, and pinworm. Jennifer Ouellette, Ars Technica, 11 Feb. 2022 Predicting Behaviors From Connections About 35 years ago, the first full-brain wiring diagram was completed for the roundworm. Quanta Magazine, 6 Dec. 2021 In fact, the only species for which there is yet a comprehensive connectome is Caenorhabditis elegans, the humble roundworm. Quanta Magazine, 6 Dec. 2021 In 2008, David Raizen and his colleagues even reported sleep in Caenorhabditis elegans, the roundworm widely used as a model organism in biology laboratories. Quanta Magazine, 18 May 2021 Researchers have achieved astonishing results by tweaking the genome of the roundworm C. elegans, extending its life span nearly 10 times — the equivalent of a person’s living 1,000 years. New York Times, 28 Apr. 2021 That’s what a team of biologists has observed in the roundworm Caenorhabditis elegans. Christopher Crockett, Scientific American, 2 Aug. 2013 See More

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

First Known Use of roundworm

1558, in the meaning defined above

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The first known use of roundworm was in 1558

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round yam

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Last Updated

25 May 2022

Cite this Entry

“Roundworm.” Dictionary, Merriam-Webster, Accessed 3 Jul. 2022.

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More Definitions for roundworm


round·​worm | \ ˈrau̇nd-ˌwərm How to pronounce roundworm (audio) \

Kids Definition of roundworm

: a worm that has a round body with no segments and is sometimes a serious parasite of people and animals


round·​worm | \ ˈrau̇n-ˌdwərm How to pronounce roundworm (audio) \

Medical Definition of roundworm

: nematode also : a related round-bodied unsegmented worm (as an acanthocephalan) as distinguished from a flatworm

More from Merriam-Webster on roundworm

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


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