Roman Hills total (5)
I believe the answer is:
seven
'roman hills total' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for seven that I've seen before include "VII" , "Little friends of ..." , "Number of Wonders of the World" , "Number of sisters in Sussex" , "Dwarfs or Wonders of the World?" .)