a store room for valuables, but also acknowledges "by extension, a private room, a bed chamber, also a Privy". It's most common use now is the term for a castle toilet.
The term refers to a medieval or Renaissance toilet or a close stool. In a castle a garderobe was usually a simple hole
discharging to the outside in a cesspit or the most, depending on the structure of the building. Such toilets were often
placed inside a small chamber, leading to the term garderobe to describe the rooms. Many can still be seen in Norman
and medieval castles and fortifications, for example at Burresheim Castle in Germay, where three garderobes are still
visible. They became obsolete with the introduction of indoor plumbing.
A description of the garderobe at Donegal Castle indicates that while it was in use, it was believed that ammonia would protect visitors 'cloaks and coats' particularly from fleas.
The garderobe in Donegal Castle..
the coats and other possessions of visitors. In Danish, Dutch,Norwegian,Germany,Russian, and Spanish, the word can
mean a cloakroom. In Latvian it means "check room".
There are several theories about the origin of this informal British term for toilet. The first and most popular, is that it
derived from the cry of the "gardyloo", from the French "regardez l'eau" (watch out for the water), which was shouted
by medieval servants as they emptied the chamber pots out of the upstairs Windows into the street. This historically
prob attic, since by the time the term 'Loo' is recorded, the expression 'gardyloo' was long obsolete.
https://en.m.wikipedia.org/wiki/Garderobe