Eastern US is mad for sweet wine (9)
I believe the answer is:
sauternes
'sweet wine' is the definition.
(I've seen this before)
'eastern us is mad' is the wordplay.
'is mad' indicates an anagram.
'eastern'+'us'='easternus'
'easternus' is an anagram of 'SAUTERNES'.
'for' acts as a link.
(Other definitions for sauternes that I've seen before include "Sweet white wine" , "A sweet Bordeaux" , "Sweet French wine" .)