Restroom (noun)

1. A room, typically in a public building, containing facilities for people to attend to personal hygiene.
2. A public toilet.

Origin:

Composed by the words "rest" and "room".

Examples:

1. I need to use the restroom.
2. The restroom is located on the first floor.
3. Please use the restroom before we leave.
4. The restroom was clean and well-stocked.
5. It's not appropriate to talk on the phone in the restroom.