Murdered solitary Cavalier? (8)
I believe the answer is:
royalist
'murdered solitary cavalier?' is the definition.
'royalist' can be an answer for 'cavalier?' (Cavaliers were royalists in the English Civil War). I am unsure of the 'murdered solitary' bit.
'solitary cavalier?' is the wordplay.
'cavalier?' indicates anagramming the letters (a cavalier or careless spelling).
'solitary' is an anagram of 'ROYALIST'.
Can you help me to learn more?
(Other definitions for royalist that I've seen before include "One pro-monarchy" , "Civil War participant" , "Monarchist" , "Supporter of monarchy" , "opponent of Republicans" .)