Definition (Source: Wikipedia)
***A bathroom is a room that may have different functions depending on the cultural context. In the most literal sense, the word bathroom means "a room with a bath". Because the traditional bathtubs have partly made way for modern showers, including steam showers, the more general definition is "a room where one bathes". There can be just a shower, just a bathtub or both; and often both plumbing fixtures are combined in the bathtub. The room may also contain a sink, often called a "wash basin", "hand basin" or "lavatory" (USA), and often a toilet fixture.
In the United States, "bathroom" commonly means "a room containing a toilet". In other countries this is usually called the "toilet" or alternatively "water closet" (WC), lavatory or "loo". In America they are categorized as a "full bathroom", containing four plumbing fixtures: bathtub, shower, toilet, and sink; "half (1/2) bath" (or "powder room") containing just a toilet and sink; and "3/4 bath" containing toilet, sink, and shower. The word is also used in the U.S. for a public toilet.