pinworm

noun

pin·​worm ˈpin-ˌwərm How to pronounce pinworm (audio)
1
: any of numerous small nematode worms (family Oxyuridae) that infest the intestines and especially the cecum of various vertebrates
especially : a worm (Enterobius vermicularis) parasitic in humans
2
: any of several rather slender insect larvae that burrow in plant tissue

Examples of pinworm in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
That burden typically clocks in at fewer than five pinworms per chipmunk, which isn’t enough to do any serious damage to the hosts. Kate Golembiewski, Discover Magazine, 1 Aug. 2024 But pinworms are most often found in preschool-aged children, says De Latour, and the worms are about the thickness of a dime — a far cry from the thick, lengthy, creepy-crawlies seen in the TikTok Shop videos. Ej Dickson, Rolling Stone, 20 Sep. 2023 Itching in the anal area is the most common indication of a pinworm infection. Samantha Lauriello, Health, 9 May 2023

Word History

First Known Use

1846, in the meaning defined at sense 1

Time Traveler
The first known use of pinworm was in 1846

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Cite this Entry

“Pinworm.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/pinworm. Accessed 11 Sep. 2025.

Kids Definition

pinworm

noun
pin·​worm -ˌwərm How to pronounce pinworm (audio)
: any of numerous small roundworms that infest the intestines of various vertebrates
especially : one that infests human beings

Medical Definition

pinworm

noun
pin·​worm ˈpin-ˌwərm How to pronounce pinworm (audio)
: any of numerous small nematode worms of the family Oxyuridae that have the tail of the female prolonged into a sharp point and infest the intestines and especially the cecum of various vertebrates
especially : a worm of the genus Enterobius (E. vermicularis) that is parasitic in humans

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