Mesozoa: Meaning and Definition of

Mes•o•zo•a

Pronunciation: (mez"u-zō'u, mes"-, mē"zu-, -su-), [key]
— n. Zool.
  1. the phylum of invertebrates comprising the mesozoans, parasitic wormlike multicellular organisms sometimes considered to be intermediate in complexity between protozoans and metazoans.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.