/ Dictionary / Index M master bath: Meaning and Definition of Find definitions for: mas'ter bath' Pronunciation: [key] a private bathroom adjoining a master bedroom. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. master-at-arms master bedroom Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language