French city only reorganised (4)
I believe the answer is:
lyon
'french city' is the definition.
(Lyon is a city in France)
'only reorganised' is the wordplay.
'reorganised' is an anagram indicator.
'only' with letters rearranged gives 'LYON'.
(Other definitions for lyon that I've seen before include "City where the Saone joins the Rhone" , "Southern French city" , "City of central France" , "River port of southeast France" , "River port, capital of the Rhone department" .)