Sentence:  In the early medieval period (1066-1300), the solution in huge stone castles was <WSD>garderobes</WSD>: small rooms that jutted out over the walls with a hole covered by a seat. Castle builders tried to site <WSD>garderobes</WSD> over a stream or a moat, but this was not always possible. 
Meaning of the word marked with <WSD> tags:  A lavatory, especially in a castle and built into the outer wall, with vent directly over the moat or midden.