Italian inn-keeper's lying about bill (7)
I believe the answer is:
padrone
'italian inn-keeper's' is the definition.
I can't tell whether this definition defines the answer.
'lying about bill' is the wordplay.
'lying' becomes 'prone' (I've seen this in another clue).
'about' is an insertion indicator.
'bill' becomes 'ad' (advertisement stuck on wall).
'prone' going around 'ad' is 'PADRONE'.
Can you help me to learn more?
(Other definitions for padrone that I've seen before include "who keeps a restaurant?" , "Italian innkeeper" , "Mafia boss" .)