/ Dictionary / Index M master sergeant: Meaning and Definition of Find definitions for: mas'ter ser'geant Pronunciation: [key] Army, Air Force, Marine Corps. a noncommissioned officer ranking next to the highest noncommissioned officer. a noncommissioned officer of one of the three top enlisted grades. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. master's degree mastership Related Content Daily Word Quiz: penchant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language