Young setter's partner round ancient city (8)
I believe the answer is:
immature
'young' is the definition.
(I know that young can be written as immature)
'setter's partner round ancient city' is the wordplay.
I cannot quite see how this works, but
'setter's' could be 'im' (I've seen this in other clues) and 'im' is found in the answer.
'partner' could be 'e' and 'e' is found in the answer.
'city' could be 'ur' (ancient Sumerian city state) and 'ur' is present in the answer.
The remaining letters 'mat' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for immature that I've seen before include "Green" , "Not yet adult or fully developed" , "Like childish behaviour" , "Lacking in development" , "Irate mum? (anag)" .)