One in Paris and Rome excited promoter (10)
I believe the answer is:
impresario
'promoter' is the definition.
(I know that promoter can be written as impresario)
'one in paris and rome excited' is the wordplay.
'one' becomes 'i' (Roman numeral).
'in' is an insertion indicator.
'and' means one lot of letters go next to another.
'excited' indicates anagramming the letters.
'paris' put after 'rome' is 'romeparis'.
'romeparis' with letters rearranged gives 'impresaro'.
'i' inserted inside 'impresaro' is 'IMPRESARIO'.
(Other definitions for impresario that I've seen before include "artistic director" , "Promoter of public entertainments" , "Producer of performing arts" , "Showman" , "Entertainer" .)