A tub or pool which is used for bathing: bathtub.

A building or area where bathing occurs.

The act of bathing.

To wash a person or animal in a bath

A room containing a shower and/or bathtub, and (typically but not necessarily) a toilet.

A lavatory: a room containing a toilet and (typically but not necessarily) a bathtub.

“Most Americans don't know 'WC' and many Brits mock 'bathroom' but almost everyone understands 'toilet' or 'lavatory'.”