River through Switzerland (5)
I believe the answer is:
rhine
'river through switzerland' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for rhine that I've seen before include "Bonn's river" , "Great river in Germany with Lorelei Rock" , "Major European river" , "Great river that flows through Germany" , "valley" .)