City on the Rhône and Saône (4)
I believe the answer is:
lyon
'city on the rhone and saone' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for lyon that I've seen before include "City where the Saone joins the Rhone" , "French city on the Rhone" , "River port of southeast France" , "City of south-central France" , "River port, capital of the Rhone department" .)