From Longman Dictionary of Contemporary Englishmen's roomˈmen’s room noun [countable] especially American English DLthe men’s toilet SYN gents British English → ladies’ room
Examples from the Corpus
men's room• None of the places I had been in seemed to have a men's room anyway.• He has worked as the men's room assistant for three years.• On the ground, when they had left the parked plane, Myeloski excused himself and went to the men's room.• After visiting the men's room at 5, the late-night club, Miller considered EarthLink's message. 