/ Dictionary / Index M Mesozoa: Meaning and Definition of Find definitions for: Mes•o•zo•a Pronunciation: (mez"u-zō'u, mes"-, mē"zu-, -su-), [key] — n. Zool. 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. mesovarium mesozoan Related Content Daily Word Quiz: clairvoyant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language