Wine valley (4)
(Other definitions for rhine that I've seen before include "fed by 8 [RHUR]" , "Major European river" , "Cologne's river" , "Great European river with Lorelei Rock" , "Great river in Germany with Lorelei Rock" .)
(Other definitions for loire that I've seen before include "France's longest river" , "Longest French river" , "River of central France" , "French river (Orleans, Tours, Nantes)" , "Current French" .)
'wine valley' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for napa that I've seen before include "Californian valley, famous for wine" , "California wine valley" , "soft skin" .)