State of Clifton Gardens (5)
I believe the answer is:
tonga
'state' is the definition.
(I know that Tonga is a state)
'of clifton gardens' is the wordplay.
'of' indicates a hidden word.
'TONGA' is hidden within 'clifton gardens'.
(Other definitions for tonga that I've seen before include "part of Polynesia" , "The Friendly Islands" , "South Pacific island group country" , "transport" , "Pacific Ocean monarchy" .)