Why is a toilet called a John, a loo, a head, or a water closet? Why do we have so many English words for the toilet anyway? Doesn’t it remind you of how the Inuit people have some 400 words for snow (which is not true, by the way)? Actually, there are still a few mysteries surrounding our slang words for toilet, but we have some educated guesses you may find interesting.

Here’s where the mystery lies. Sir John Harrington, a courtier in the court of Queen Elizabeth I, is usually credited with inventing the modern flush toilet. He wrote about it in his book, The Metamorphosis of Ajax, although the device described in the book was really more of a literary device than a mechanical one, meant as an allegory. More specifically, it was a political statement about the “stercus” (feces) that was ruining society.
Still, Harrington is believed to be the inventor of the modern flush toilet. Supposedly he had one in his mansion and also installed one for the queen in the palace around 1596. How it worked was that by pulling on a cord next to the toilet bowl, water would rush in from the “water closet” to flush away the waste. This is why toilets in the UK, France and other European countries are still either called water closets or designated by the letters WC.
So why is a toilet called a John? Because we believe the modern flush toilet was invented by a man named John. However, there is evidence that suggests that flush toilets were being used by ancient civilizations as early as the 26th century BC!
There is another theory as to why a toilet is called a John, although it is likely nothing more than a folk tale, as are most stories of the legendary King Arthur. The story goes that while the king was away fighting the Saxons, he left his brother John in charge. Upon his return, Arthur was so upset with the way John had run things, he named the toilet after him.
There was a man named Thomas Crapper. He was a plumber, as a matter of fact, who may have tinkered with and/or improved the toilet, but he was not the inventor. In fact, it’s not even very likely that the English slang word ‘crap’ comes from his name. It probably came from the Old French word ‘crappe,’ meaning waste or rejected matter. The word ‘crap’ first appeared in the Oxford English Dictionary in 1846. Thomas Crapper was only ten years old at the time, so he probably had nothing to do with the coinage of the term.
In the UK, a toilet is often called a loo. This comes from the French phrase, “Garde l’eau.” In medieval times, before people figured out basic sanitary practices and personal hygiene, before they realized that throwing excrement out in the street was an easy way to spread horrible diseases, that is exactly what they did.
When the bucket that served as a toilet needed emptying, they would simply dump it out in the gutter, sometimes from the second or third story of a building. To warn the pedestrians below, they would yell, “Garde l’eau!” which basically means, “Watch out for the water.” The phrase came to England, where it morphed into something that sounded more like, “Gardy loo,” and that is where the British term ‘loo’ comes from.
The front part of a ship has long been called the ship’s bow or head. Before modern plumbing and chemical cleaning products made it onto boats, the toilet was situated in the front of the ship so that the sea water splashing up onto the ship could naturally clean it. The position of the toilet at the front of the ship is the reason why a marine toilet is called a head.
There are certainly plenty of slang terms for the toilet in English. Now that you understand how at least three of them came about, you can choose more wisely what you’d like to call yours.