One confused royalist! (8)
I believe the answer is:
solitary
'one' is the definition.
(thesaurus)
'confused royalist' is the wordplay.
'confused' indicates anagramming the letters.
'royalist' anagrammed gives 'SOLITARY'.
(Other definitions for solitary that I've seen before include "Secluded, isolated" , "friendless" , "Done alone" , "Hermit living alone" , "Confinement" .)