nematode

noun

nem·​a·​tode ˈne-mə-ˌtōd How to pronounce nematode (audio)
ˈnē-
: any of a phylum (Nematoda or Nemata) of elongated cylindrical worms parasitic in animals or plants or free-living in soil or water

called also roundworm

Examples of nematode in a Sentence

Recent Examples on the Web
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Chalasani’s lab at Salk in La Jolla has shown, first in nematodes and then in mice, how this combination of proteins and sound can allow activation and deactivation of individual cells to treat conditions without surgery. Paul Sisson, San Diego Union-Tribune, 13 Apr. 2026 Research shows marigolds can repel some nematodes — tiny worm-like organisms in the soil that damage plant roots. Lauren Jarvis-Gibson, Fort Worth Star-Telegram, 11 Apr. 2026 Sparse, strategic placement may still offer nematode-repelling benefits without the pest-attracting downside. Lauren Jarvis-Gibson, Kansas City Star, 10 Apr. 2026 To do so, Vidal-Gadea would knock out genes in nematodes, then have those worms attempt to burrow in dirt or go for a swim to see what happened to their muscles. Megan Molteni, STAT, 27 Mar. 2026 See All Example Sentences for nematode

Word History

Etymology

ultimately from Greek nēmat-, nēma

First Known Use

1865, in the meaning defined above

Time Traveler
The first known use of nematode was in 1865

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Cite this Entry

“Nematode.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/nematode. Accessed 17 Apr. 2026.

Kids Definition

nematode

noun
nem·​a·​tode ˈnem-ə-ˌtōd How to pronounce nematode (audio)
: any of a major group of long cylinder-shaped worms that are parasites in animals or plants or live in soil or water

called also roundworm

Medical Definition

nematode

1 of 2 adjective
nem·​a·​tode ˈnem-ə-ˌtōd How to pronounce nematode (audio)
: of or relating to the phylum Nematoda

nematode

2 of 2 noun
: any worm of the phylum Nematoda

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