He likes people looking in at his window (10)
I believe the answer is:
shopkeeper
This might be a double definition.
'he likes people looking' is the first definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'at his window' is the second definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for shopkeeper that I've seen before include "E.g. newsagent" , "perhaps Napoleon's man in England?" , "Tradesperson" , "Counter-agent" .)