/ Dictionary / Index M meantone system: Meaning and Definition of Find definitions for: mean'tone sys"tem Pronunciation: (mēn'tōn"), [key] — Music. Music. a system for tuning keyboard instruments, used before the development of tuning by equal temperament and considered practical only for tonalities of not more than two sharps or flats. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. meantime mean value Related Content Daily Word Quiz: abominable Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language