Great air-cooler finally kept wine cold (9)
I believe the answer is:
fantastic
'great' is the definition.
(thesaurus)
'air-cooler finally kept wine cold' is the wordplay.
'air-cooler' becomes 'fan'.
'finally' says to take the final letters.
'wine' becomes 'asti' (I've seen this before).
'cold' becomes 'c' (eg on taps).
The final letter of 'kept' is 't'.
'fan'+'t'+'asti'+'c'='FANTASTIC'
(Other definitions for fantastic that I've seen before include "Brilliant or unbelievable" , "Marvellous" , "Wild" , "Terrific" , "Extravagant, superb or beyond belief" .)