Rome turned out to be extra (4)

I believe the answer is:

'to be extra' is the definition.
(both can mean additional)

'rome turned' is the wordplay.
'turned' indicates an anagram.
'rome' is an anagram of 'MORE'.

'out' acts as a link.

(Other definitions for more that I've seen before include "Greater quantity or number" , "Extra (for Sir Thomas?)" , "See 9" , "What Oliver wanted" , "author" .)

I've seen this clue in The Mirror.

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