Something in your eye when drinking last of precious wine (7)
I believe the answer is:
retsina
'wine' is the definition.
(type of Greek wine)
'something in your eye when drinking last of precious' is the wordplay.
'something in your eye' becomes 'retina' (I've seen this in another clue).
'when drinking' means one lot of letters goes inside another.
'last of' says to take the final letters.
The final letter of 'precious' is 's'.
'retina' going around 's' is 'RETSINA'.
(Other definitions for retsina that I've seen before include "Flavoured Greek white wine - nastier brand" , "Greek white wine flavoured with resin" , "Greek wine - nastier sort" , "Nastier (anag) - white (or rose) wine" , "S European wine" .)