John of Salisbury (3)

I believe the answer is:
loo
'john of salisbury' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for loo that I've seen before include "Card game; the 'smallest room'" , "Lavatory - old card game" , "Ladies, perhaps" , "Little boys' room" , "Privy" .)