Loo (noun)

1. A toilet.
2. A lavatory.

Origin:

Mid 18th century: of uncertain origin; perhaps from french lieu "place".

Examples:

1. She quickly excused herself to go to the loo.
2. The loo was out of order so he had to hold it in until he got home.
3. The public loo was dirty and smelled bad.
4. The loo was located at the end of the hallway.
5. He couldn't wait any longer and had to use the nearest loo.