The word 'toilet' is correct and usable in written English.
You can use it to refer to a room with a flush toilet where one can go to use the restroom. For example, "The building had a public restroom with two toilets in it."
Dictionary
toilet
noun
Personal grooming: washing, dressing, etc.
Exact(60)
I winced in sympathy at female tennis players who have their periods during Wimbledon, when they must wear white and are allowed one toilet break per set.
The bed, bathroom, toilet and TV come as a modular unit, the "cubi", which can be quickly and cheaply installed, creating minimal environmental impact and bringing new life to empty buildings.
In Kill Me Now, none of the non-disabled characters ever go to the toilet.
Tobin, who set up the organisation in 1999 in a toilet – removing the sink to make way for a desk – said the donations will help them to treat the 300 people they see annually.
The official investigation found that the breeding ground for the Sars coronavirus in the Amoy blocks was the toilet system.
I've written for a few years now about the dreadful state of things in the developing world, where girls leave school because they don't have a toilet or sanitary protection, and use sand or rags, or sell sex to buy pads.
"Come the zombie apocalypse, we'll be OK," declares Siobhan McSweeney as she surveys a pile of toilet rolls big enough to supply a small village.
I wouldn't buy a big pack of toilet paper, because the four pack seemed like enough.
Dress code is informal: street clothes, swimwear, underclothes, collar and tie, religious robes... Girls squat down to urinate wherever there is a dip in the sand – there are no toilet facilities.
Only a third of the one million or so citizens have access to a functioning toilet.
The need to increase toilet coverage worldwide is now understood to be as crucial as water provision in improving public health and reducing poverty, yet there are still few affordable, off-the-shelf technologies appropriate for meeting the sanitation needs of the 2.5 billion people living without access to an affordable clean toilet.
Write better and faster with AI suggestions while staying true to your unique style.
Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.

Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com