Eccentric royalist is quite reclusive (8)
I believe the answer is:
solitary
'quite reclusive' is the definition.
'solitary' can be an answer for 'reclusive' (I've seen this before). I am not certain of the 'quite' bit.
'eccentric royalist' is the wordplay.
'eccentric' indicates an anagram.
'royalist' with letters rearranged gives 'SOLITARY'.
'is' is the link.
Can you help me to learn more?
(Other definitions for solitary that I've seen before include "friendless" , "Left alone" , "Being the only one" , "unique" , "Hermit living alone" .)