Great fizzy drink -- it's flipping cold (9)
I believe the answer is:
fantastic
'great' is the definition.
(thesaurus)
'fizzy drink it's flipping cold' is the wordplay.
'fizzy drink' becomes 'fanta' (brand of fizzy drink).
'flipping' says the letters should be written in reverse.
'cold' becomes 'c' (eg on taps).
'its' backwards is 'sti'.
'fanta'+'sti'+'c'='FANTASTIC'
(Other definitions for fantastic that I've seen before include "Great!" , "Super!" , "Terrific" , "Splendid, excellent" , "Illusory - excellent!" .)