IPA: /ˈrɛs.tɹuːm/
KK: /ˈrɛsˌtruːm/
A room that has toilets and sinks for people to use, usually found in public places.
I need to find the restroom before the movie starts.
Restroom → The word is formed from "rest" (from Old French *rester*, meaning to remain or stay) and "room" (from Old English *rum*, meaning space or area). A restroom is a space where one can remain for personal needs.
Think of a place where you can 'stay' ('rest') in a 'space' ('room') for personal needs.