Ice giant turning around rapidly, awesome initially (7)
I believe the answer is:
'ice' is the definition.
(I know that granita is a type of sorbet)
'giant turning around rapidly awesome initially' is the wordplay.
'turning' is an anagram indicator.
'around' indicates putting letters inside.
'initially' suggests taking the first letters.
The initial letters of 'rapidly awesome' is 'ra'.
'giant' is an anagram of 'gnita'.
'gnita' placed around 'ra' is 'GRANITA'.
(Other definitions for granita that I've seen before include "type of sorbet" , "rough ice" , "cold dessert" , "Grainy flavoured water ice - Riga ant (anag)" , "Crushed ice drink" .)