/ Dictionary / Index M membranous: Meaning and Definition of Find definitions for: mem•bra•nous Pronunciation: (mem'bru-nus), [key] — adj. consisting of, of the nature of, or resembling membrane. characterized by the formation of a membrane. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: membranous (Thesaurus) membranophone membranous labyrinth Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language