/ Dictionary / Index M membranous labyrinth: Meaning and Definition of Find definitions for: mem'branous lab'yrinth. Pronunciation: [key] See under(def. 6a). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. membranous meme Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language