Alps-to-Arles river
I believe the answer is:
'alps-to-arles river' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for rhone that I've seen before include "Current" , "River flowing from Alps to the French Med" , "wherein runs rain in Arbroath" , "One following long course" , "River running through France to the Med" .)