Unusually solitary Queen fan? (8)
I believe the answer is:
royalist
'queen fan?' is the definition.
(supporter of the monarchy)
'unusually solitary' is the wordplay.
'unusually' indicates an anagram.
'solitary' is an anagram of 'ROYALIST'.
(Other definitions for royalist that I've seen before include "one in civil war" , "One pro-monarchy" , "Civil War participant" , "Civil War Cavalier" , "Monarch's supporter" .)