/ Dictionary / Index M mumu: Meaning and Definition of Find definitions for: mu•mu Pronunciation: (m'm), [key] — n. muumuu. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mumpsimus mun. Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language