[ 'aʃhɛlmɪnθ , 'ask- ]
■ noun ( plural ~s or ~es ) Zoology a typically worm-like invertebrate of a large group that lack a well-developed coelom and blood vessels and include the nematodes, rotifers, and water bears.
Origin
from mod. L. Aschelminthes (former phylum name), from Gk askos 'sac' + helminth 'worm' (from the former belief that animals of this group had a fluid-filled internal sac).