Rat who often catches you out would be Arkwright, e.g. (10)
I believe the answer is:
shopkeeper
'rat who often catches you out would be arkwright' is the definition.
The definition and answer can be both people as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'e g' is the wordplay.
I cannot really understand how this works, but
'e' is found in the answer.
'g' could be 'k' (synonyms) and 'k' is found in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for shopkeeper that I've seen before include "Tradesperson" , "E.g. newsagent" , "Counter-agent" , "perhaps Napoleon's man in England?" .)