nem·​a·​tode ˈne-mə-ˌtōd How to pronounce nematode (audio)
: 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 The fungus then uses proteases to digest nematodes that get stuck in its hyphae. Elizabeth Rayne, Ars Technica, 18 Dec. 2023 Biologists have been drawn to the elegant simplicity of nematode biology for many decades. Lauren Leffer, Scientific American, 21 Aug. 2023 The parasitic nematodes are, as their name suggests, typically found in rats. Beth Mole, Ars Technica, 22 Sep. 2023 Soil is made up of its mineral constituents, organic matter, air, water and living organisms—from earthworms and larvae to nematodes and microscopic bacteria and fungi. Elizabeth Waddington, Treehugger, 16 May 2023 Start your nematode control program by locating seeds or transplants of tomatoes that have some nematode resistance. Tom MacCubbin,, 15 Jan. 2022 Florida has a big nematode problem, so roses are grafted on nematode-resistant Fortuniana rootstock. Rita Perwich, San Diego Union-Tribune, 4 Nov. 2023 Marigolds are known to produce various toxins from their roots that deter nematodes and can naturally protect susceptible plants when planted together. Derek Carwood, Better Homes & Gardens, 28 Oct. 2023 Previously, the longest a nematode had been recorded to survive in cryptobiosis was just 39 years. Will Sullivan, Smithsonian Magazine, 28 July 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'nematode.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


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

Dictionary Entries Near nematode

Cite this Entry

“Nematode.” Dictionary, Merriam-Webster, Accessed 26 Feb. 2024.

Kids Definition


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


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


2 of 2 noun
: any worm of the phylum Nematoda

More from Merriam-Webster on nematode

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