[ad_1] noun Zoology.
- a major grouping (formerly a phylum) of small-to-microscopic pseudocoelomate organisms, as the rotifers, nematodes, and gastrotriches, all of which are now classified as separate phyla.
n.
- A phylum of the Metazoa that includes nematodes and other roundworms that are nonsegmented, bilaterally symmetrical, and cylindrical in form, with a pseudocele body cavity and rounded or pointed ends.