/ Dictionary / Index M mastery: Meaning and Definition of Find definitions for: mas•ter•y Pronunciation: (mas'tu-rē, mä'stu-), [key] — pl. -ter•ies command or grasp, as of a subject: a mastery of Italian. superiority or victory: mastery over one's enemies. the act of mastering. expert skill or knowledge. the state of being master; power of command or control. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mastery (Thesaurus) masterwort mast hasp Related Content Daily Word Quiz: censure Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language