/ Dictionary / Index O overmaster: Meaning and Definition of Find definitions for: o•ver•mas•ter Pronunciation: (ō"vur-mas'tur, -mä'stur), [key] — v.t. to gain mastery over; conquer; overpower: The sudden impulse had quite overmastered me. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: overmaster (Thesaurus) overmantel overmatch Related Content Daily Word Quiz: blanch Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language