/ Dictionary / Index M mezzo-soprano clef: Meaning and Definition of Find definitions for: mez'zo-sopran'o clef" Pronunciation: [key] a C clef locating middle C on the line next to the lowest line of the staff. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mezzo-soprano mezzotint Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language