Watercloset

Part of speech: noun

Definitions

1. A toilet fixture set in a small private room, often flushed with water to carry waste away ; the enclosed compartment or small room in which such a toilet is installed
2. A flushing lavatory bowl enclosed in a small private chamber ; the tiny room housing that fixture within a building
3. A sanitary toilet installed in a compact separate room ; the small enclosed space in a home or building that holds it

Etymology: The "closet" here has nothing to do with a wardrobe. In Middle English a "closet" was a small private room, from Old French "closet", a diminutive of "clos" meaning an enclosed space, so a closet was simply a little enclosure set apart for private use. Attaching "water" to it produced a room for the lavatory, and the compound captures the old euphemism of the era: the fitting was named for the room and the flushing water rather than for its function. The word is a plain compound, built from "water" and "closet" in the sense of a private room. Its ordinary meaning has stayed fixed since it was formed, with no dramatic shift, so the interest lies in the older sense of "closet" that most speakers no longer recognise.