Month attorney finally framed acceptable system of rule (8)
I believe the answer is:
monarchy
'system of rule' is the definition.
'month attorney finally framed acceptable' is the wordplay.
'month' becomes 'M' (standard abbreviation).
'attorney finally' becomes 'archy' (I can't justify this - if you can you should give a lot more credence to this answer).
'framed' indicates putting letters inside.
'acceptable' becomes 'on' (as opposed to not on, unacceptable).
'm'+'archy'='marchy'
'marchy' enclosing 'on' is 'MONARCHY'.
Can you help me to learn more?
(Other definitions for monarchy that I've seen before include "Kingship system" , "kind of government" , "sort of government" , "realm" , "Kingdom - kingship" .)