men's room

Meanings

1. A restroom intended for use by males, often including urinals in addition to toilet stalls.
2. Other rooms intended for use by men, as waiting rooms, dressing rooms, locker rooms, etc.

Etymology

Originally a clipped form of gentlemen's room, originally a separate waiting room for men in public buildings such as railway stations but by the appearance of men's room also used as a euphemism for men's lavatories.