Nemathelminthes

noun plural
Nem·​a·​thel·​min·​thes | \ -ˌthel-ˈmin(t)-(ˌ)thēz How to pronounce Nemathelminthes (audio) \

Medical Definition of Nemathelminthes

in some classifications
: a phylum including the nematodes and horsehair worms and sometimes the acanthocephalans, rotifers, gastrotrichs, and minute marine organisms of a related class (Kinorhyncha) which are all more or less wormlike animals with a cylindrical unsegmented body covered by an ectoderm without cilia that secretes an external cuticle