washroom
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.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.