Fancy drink, with sherry having been emptied (7)
I believe the answer is:
fantasy
'fancy' is the definition.
(synonyms)
'drink with sherry having been emptied' is the wordplay.
'drink' becomes 'Fanta' (brand of fizzy drink).
'with' says to put letters next to each other.
'having been emptied' says to hollow out the word (remove centre letters) (the inside letters are emptied out).
'sherry' with its middle removed is 'sy'.
'fanta'+'sy'='FANTASY'
(Other definitions for fantasy that I've seen before include "The imagining of what is impossible" , "Activity of imagining improbable things" , "Fay tans badly and forms a mental image" , "Whimsical, imaginative, notion" , "Unreal idea" .)