/ Dictionary / Index M mu meson: Meaning and Definition of Find definitions for: mu' me'son Pronunciation: [key] (no longer in technical use) muon. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mumbo jumbo Mumetal Related Content Daily Word Quiz: belligerent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language