Unpopular revenue generator possibly shares around excessive returns (5,4)
I believe the answer is:
speed trap
'unpopular revenue generator' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'shares around excessive returns' is the wordplay.
'shares' becomes 'parts' (share can mean a part or division of something).
'around' is an insertion indicator.
'excessive' becomes 'deep' (I can't justify this - if you can you should believe this answer much more).
'returns' is a reversal indicator.
'parts' placed around 'deep' is 'partdeeps'.
'partdeeps' in reverse letter order is 'SPEED TRAP'.
'possibly' acts as a link.
Can you help me to learn more?
(Other definitions for speed trap that I've seen before include "curse of drivers?" , "police operation" , "road safety measure" , "Set-up to catch fast drivers" , "Hazard for fast motorist" .)