Decadent place has honey left over (7)
I believe the answer is:
babylon
'decadent place' is the definition.
The definition and answer can be both locations as well as being singular nouns.
Perhaps you can see a link between them that I can't see?
'has honey left over' is the wordplay.
'has honey' becomes 'baby' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'left' becomes 'l' (common abbreviation).
'over' becomes 'on' (physically on top of).
'baby'+'l'+'on'='BABYLON'
Can you help me to learn more?
(Other definitions for babylon that I've seen before include "Ancient Mesopotamian city" , "City noted for wealth and wickedness in Bible" , "Site of hanging gardens" , "Bony lab found in the ancient city" , "Sin City of the Bible" .)