bathroom
A room with a toilet and usually a sink and shower.
A bathroom is a room in a house or building that contains a toilet and usually a sink for washing hands. Most bathrooms also have a bathtub or shower for bathing.
In homes, bathrooms are private spaces where people go to wash up, brush their teeth, use the toilet, and take showers or baths. Public buildings like schools, restaurants, and offices have bathrooms too, often called restrooms or washrooms. These usually just have toilets and sinks, without bathtubs.
People sometimes use “bathroom” as a polite way to avoid saying they need to use the toilet. A student might ask their teacher, “May I go to the bathroom?” when what they really mean is they need to use the toilet. This polite usage has become so common that many people say they're “going to the bathroom” even when they're just washing their hands or fixing their hair.
Different countries have different words for this room. In Britain, people often say “loo” or “toilet,” and they reserve “bathroom” for rooms that actually contain a bath. Americans typically say “bathroom” regardless of whether there's a bathtub present.