toilet
The term carries a heavy geographic divide in connotation. In British English, it is the standard, neutral word for the plumbing fixture and the room containing it. In American English, the word refers strictly to the porcelain bowl itself; using it to describe the room is often perceived as overly blunt or slightly vulgar, where terms like restroom or bathroom are preferred. There is a distinct shift in tone when used as a verb. While the noun is mundane and functional, the verb form evokes an old-fashioned, formal sense of dressing and grooming. This usage is rare in modern conversation and usually appears in historical literature or highly stylized prose to describe the ritual of preparing one's appearance.
Countable when referring to the physical porcelain appliance in a bathroom. Uncountable when referring to the general system of sewage and waste disposal in a city.