noun
roundworms; nematodes
Taxonomic term referring to the phylum Nematoda (roundworms). Used in biological and zoological contexts.
円虫類には、植物に寄生する種も多く含まれる。
Roundworms include many species that parasitize plants.
線虫 is a more common term for nematodes, while 円虫類 is a formal taxonomic group name.
From 円 (round) + 虫 (worm) + 類 (category), a direct calque of the taxonomic concept 'roundworms'.