“Bathroom” is a strange euphemism.  Most bathrooms do not have baths.  For that matter, a “restroom” should be a place where the primary activity is resting, but none of them have benches or beds.  A more accurate name would be “the toilet room.”

I used to wonder why we prefer bland misnomers for such a simple, common area, until I shared this thought with a class of high schoolers once, after which some of the more adventurous among them would come up to my desk and ask, “Excuse me, sir, may I please go to the toilet room?”  Much giggling ensued.

So, “bathroom” it is.