/ Dictionary / Index M metanephros: Meaning and Definition of Find definitions for: met•a•neph•ros Pronunciation: (met"u-nef'ros), [key] — pl. -roi one of the three embryonic excretory organs of higher vertebrates, becoming the permanent and functional kidney. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. metamorphous Metanira Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language