A friend finds ancient city incompetent (7)

I believe the answer is:

amateur

'incompetent' is the definition.
(amateur can mean incompetent or inexpert)

'a friend finds ancient city' is the wordplay.
'friend' becomes 'mate' (mate is a kind of friend).
'finds' means one lot of letters go next to another.
'ancient city' becomes 'ur' (ancient Sumerian city state).
'a'+'mate'+'ur'='AMATEUR'

(Other definitions for amateur that I've seen before include "A non-professional sportsman" , "Unprofessional" , "Layperson" , "He's not professional" , "Lay person" .)

I've seen this clue in The Daily Express.

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