Breadcrumb Home > Dictionary > Index M M.S.A.: Meaning and Definition of Find definitions for: M.S.A. Pronunciation: [key] Master of Science in Agriculture. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. MS M.S.A.E. ✖ Related Content Daily Word Quiz: derogate Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language