River of wine! (5)
I believe the answer is:
rhine
I believe this is a double definition.
'river' is the first definition.
(Rhine River is an example)
'wine' is the second definition.
(Rhine wine is an example)
'of' acts as a link.
(Other definitions for rhine that I've seen before include "Bonn's river" , "Flower" , "fed by 8 [RHUR]" , "Great German river with Lorelei Rock" , "valley" .)