Have you ever seen the letters “WC” outside a public bathroom and wondered what they mean? You’re not alone. People across the globe are often puzzled by this term. “WC” stands for “water closet,” a phrase used to describe a small room that contains a toilet and sometimes a sink.

While it may sound fancy or outdated, it’s just another way of saying bathroom, restroom, or loo. But none of those terms make perfect sense either. In 2020, a couple named Shelby and Dylan posted a TikTok where they debated the term “washroom.” Dylan asked, “What are they washing in there?” to which Shelby replied, “Do you rest in a restroom?”

The video sparked a fun discussion online. One user joked they asked for the washroom at Disneyland and were sent to a laundromat. Another laughed, “Wait ‘til he finds out about water closets.”

According to Merriam-Webster, a water closet is “a compartment with a toilet.” The term dates back to when rooms served different purposes—bathing, resting, or toileting. Today, depending on your country, people say bathroom, restroom, lavatory, washroom, or WC. “WC” is still common in signs across airports, hotels, and international venues.