Complain audibly at drink (4)
I believe the answer is:
wine
'drink' is the definition.
(wine is an alcoholic drink)
'complain audibly' is the wordplay.
'complain' becomes 'whine' (whining is a kind of complaining).
'audibly' indicates a 'sounds like' (homophone) clue.
'whine' is a homophone of 'WINE'.
'at' acts as a link.
(Other definitions for wine that I've seen before include "A sweet white cargo of Masefield's" , "Fermented grape juice" , "Drink made from grapes" , "See 18" , "Frascati, perhaps" .)