White wine aperitif (3)
I believe the answer is:
'white wine aperitif' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for kir that I've seen before include "Blackcurrant drink" , "White wine with blackcurrant syrup" , "Mixture of white wine and cassis" , "Cocktail" , "Drink of white wine and cassis" .)