Double helping of sweet wine (4)
I believe the answer is:
twin
'double' is the definition.
(thesaurus)
'helping of sweet wine' is the wordplay.
'helping of' indicates the answer is hidden within the clue (I've seen this in other clues).
'TWIN' can be found hidden inside 'sweet wine'.
(Other definitions for twin that I've seen before include "Identical or very similar" , "Make association" , "Very much like" , "This set is matching jumper and cardigan" , "(Town) paired with another" .)