City rising in national importance (5)
I believe the answer is:
milan
'city' is the definition.
(Milan is an example)
'rising in national importance' is the wordplay.
'rising' says the letters should be written backwards (going up in a down clue).
'in' indicates the answer is hidden within the clue.
'nalim' is hidden within 'national importance'.
'nalim' backwards is 'MILAN'.
(Other definitions for milan that I've seen before include "Doorstep deliverer" , "Northern Italian city" , "Capital of Lombardy" , "European city" , "N. Italian city" .)