Civil War dissenter (8)
I believe the answer is:
leveller
'civil war dissenter' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for leveller that I've seen before include "doing a demolition job?" , "Radical dissenter during English Civil War" , "''Death the ...'' (James Shirley)" , "Egalitarian" , "'Death is the great . . . . . . . .'" .)