round·worm | \ˈrau̇nd-ˌwərm \

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

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In addition to highlighting the contents of a typical 17th-century Danish diet, the latrines reveal the poor sanitary conditions of the period—roundworm, tapeworm and whipworm eggs were all present in the deposits. Meilan Solly, Smithsonian, "Archaeologists Unseal 17th-Century Danish Latrines to Discover Copenhageners’ Dietary Habits," 9 July 2018 Often referred to as roundworms, nematodes are not closely related to true worms. The Editors Of Organic Life, Good Housekeeping, "What Are Nematodes? Are They Friendly Worms? Or Deadly Parasites?," 1 Mar. 2017 These plant parasites are NOT the same roundworms as the filarial nematodes, that infect the human body, spread diseases and cause havok on the immune system. The Editors Of Organic Life, Good Housekeeping, "What Are Nematodes? Are They Friendly Worms? Or Deadly Parasites?," 1 Mar. 2017 These crippling and even fatal diseases include African sleeping sickness, a brain-eating amoeba, hookworm, roundworms that infiltrate the lymphatic system, and malaria. Bradley J. Fikes,, "UCSD steps up fight against tropical parasitical diseases," 4 July 2018 This is the case in trioecious nematodes, a type of roundworm with three sexes: male, female and hermaphrodite. Katherine J. Wu, Smithsonian, "Alternatives to Heterosexual Pairings, Brought to You By Non-Human Animals," 28 June 2018 Froehlich also discovered that the dogs didn’t receive their vaccinations and that some previously had roundworm, among other problems, the Republic reported. Ryan Gaydos, Fox News, "Wife of U-Haul billionaire allegedly dumps sick dogs on charity, agrees to pay medical bills after nasty spat," 27 June 2018 Dirofilaria repens is a long parasitic roundworm that is spread by mosquitoes, according to the Centers for Disease Control and Prevention. Lindsey Bever,, "Blemishes moving around Russian woman's face turned out to be a parasitic worm," 22 June 2018 Kenyon had revolutionized aging research with her discovery that a single-gene mutation could double the lifespan of a tiny roundworm called C. elegans. Rob Waters, STAT, "Her bio reads like Silicon Valley fan fiction. At 23, she’s investing millions in the quest to defy death," 22 May 2018

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.

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First Known Use of roundworm

1558, in the meaning defined above

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Dictionary Entries near roundworm

round window




round yam



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Time Traveler for roundworm

The first known use of roundworm was in 1558

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More Definitions for roundworm



English Language Learners Definition of roundworm

: a small worm with a long, round body that lives inside the bodies of people and animals


round·worm | \ˈrau̇nd-ˌwərm \

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 \

Medical Definition of roundworm 

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

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