Many people are only now discovering what the letters “WC” on restroom signs actually mean. While in the U.S., words like restroom, bathroom, or even lavatory are more common, the term WC continues to appear in public places worldwide — and often leaves people puzzled.

A recent social media post sparked curiosity, with one user commenting, “I’m so glad someone asked this because I’ve been wondering for years!” Another admitted, “I can’t believe I’ve seen WC signs my whole life and never knew what it meant.”

So, what does WC stand for?
It turns out that WC means “Water Closet.” The term dates back to the early 1900s when toilets were first introduced into homes. At that time, many houses already had separate rooms for bathing. Since there wasn’t a dedicated space for toilets, they were often installed in small closets with running water — and the name water closet was born.

Even today, the abbreviation WC is used to describe a small room with just a toilet, especially in places like Europe and Asia. As Plumb World explains, “WC is used instead of bathroom to describe a space that has a toilet but no bath.” So, the next time you see a WC sign, you’ll know it’s not just a random set of letters — it’s a little piece of history about how indoor plumbing began.