The two letters **WC** on restroom signs stand for **“water closet,”** an old English expression for a private room containing a toilet. Today, the abbreviation may seem strange, but it remains widely recognized, especially in Europe. Instead of writing a longer description, WC became a simple and practical way to identify a toilet, regardless of language.

The history behind the term is connected to the development of the modern toilet. In 1596, Sir John Harington described an early flushable toilet that used water to remove waste. In 1775, Alexander Cumming patented an improved design with an S-shaped water trap, which helped stop unpleasant sewer gases from entering buildings.

As indoor plumbing became more common during the 19th century, the phrase **“water closet”** was increasingly used to describe a room containing a toilet. Eventually, the two words were shortened to **WC**, creating a brief label that was easy to place on signs and understand.

Language changed differently in various parts of the world. In the United States, **“bathroom”** and **“restroom”** became the more common terms, while WC continued to be widely used across Europe. As a result, many Americans are most likely to see the abbreviation when traveling overseas.

So, the next time you see **WC** on a door, it is simply an old abbreviation that survived into modern times. What once meant **“water closet”** has become a familiar international sign pointing to one of the most basic facilities in any public building.