Drink found in garrets in Athens (7)
I believe the answer is:
retsina
'drink' is the definition.
(retsina is a kind of drink)
'in garrets in athens' is the wordplay.
'in' indicates a hidden word.
'RETSINA' is hidden within 'garrets in athens'.
'found' acts as a link.
(Other definitions for retsina that I've seen before include "Nastier (anag) - white (or rose) wine" , "Greek drink" , "Type of Greek wine" , "Flavoured Greek white wine - nastier brand" , "Greek wine - nastier sort" .)