Sparkling wine region (4)
I believe the answer is:
asti
'sparkling wine region' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for asti that I've seen before include "Sparkling white wine" , "White wine named after a town in Piedmont" , "Italian drunk" , "Italian town producing sparkling wine" , "Italian white wine" .)