washroom
n. countable B1 Intermediate US //ˈwɑʃˌɹum// UK //wˈɒʃɹuːm// wash·room
n. a room in a building where you can wash your hands and face. It is a polite or formal way to say 'toilet' or 'bathroom'.
n. a room containing a washbasin and typically a mirror, used for washing the hands and face. Often used as a euphemism for a toilet or bathroom in professional or formal contexts.
The washroom is located just down the hallway to the left.
After the long flight, the passengers were relieved to find a clean washroom in the terminal.
The hotel lobby features a spacious marble washroom designed for guests to freshen up before entering the main dining hall for the evening gala.
From wash + room in reference to its sinks, but generally used euphemistically outside of Canada and the United States.