1) Aschelminthes 2) Phylum 3) Phylum aschelminthes 4) Phylum nematoda 1) Aschelminthes 
A class of unsegmented helminths with fundamental bilateral symmetry and secondary triradiate symmetry of the oral and oesophageal structures. Many species are parasites. ... (12 Dec 1998) ... 
(nem″ә-to´dә) the roundworms, a class of helminths (phylum Aschelminthes), many of which are parasites; some classifications consider this a phylum, others call it the class Nemathelminthes, and others consider it a class of phylum Nemathelminthes.
Type: Term Pronunciation: nem′ă-tō′dă Definitions: 1. The roundworms, a large phylum that includes many of the helminths parasitic in humans and a far greater number of plant-parasitic and free-living soil and aquatic nonparasitic species. For practical purposes, the parasitic nematodes may be placed in two groups, based ...
[n] - unsegmented worms: roundworms
phylum comprising roundworms
phylum Nematoda noun unsegmented worms: roundworms; threadworms; eelworms