Wine included in feast is (4)
I believe the answer is:
asti
'wine' is the definition.
(I've seen this before)
'included in feast is' is the wordplay.
'included in' says the answer is hidden in the clue.
'ASTI' is hidden within 'feast is'.
(Other definitions for asti that I've seen before include "Alcohol" , "Capital of a north-west Italian province, known for its sparking wine" , "Sparkling drink" , "Italian town producing sparkling wine" , "It's a (anag) - wine" .)