Peer losing case, every twelve months (4)
I believe the answer is:
earl
'peer' is the definition.
(I know that earl is a type of peer)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for earl that I've seen before include "Peer (Br.)" , "British noble" , "Noble title" , "A real titled lord" , "British nobleman" .)