roundworm

noun

round·​worm ˈrau̇nd-ˌwərm 

: 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

About 28 percent of the samples contained whipworm or roundworm eggs, whereas others had traces of Giardia duodenalis. —Claire Cameron, Scientific American, 22 Dec. 2025

Scientists analyzing the sewer drains from the Roman fort Vindolanda (near Hadrian’s Wall in northern England) found three types of intestinal parasites—roundworm,whipworm, and Giardia duodenalis. —Laura Baisas, Popular Science, 19 Dec. 2025

This acid is created by gut bacteria as a protective mechanism and previous research from the team has shown it to extend the life of roundworms and fruit flies. —New Atlas, 14 Nov. 2025

In addition, raccoon feces may contain Baylisascaris roundworm eggs, which can infect humans and lead to nerve damage or blindness. —Arricca Elin Sansone, Southern Living, 18 Oct. 2025

Word History

First Known Use

1558, in the meaning defined above

Kids Definition

roundworm

noun

round·​worm ˈrau̇n-ˌdwərm 

: a nematode worm (as a hookworm)

also : a related round-bodied worm without segments as compared to a flatworm

Medical Definition

roundworm

noun

round·​worm ˈrau̇n-ˌdwərm 

: nematode

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