Concerns Will and Earl from Oklahoma (6)
I believe the answer is:
estate
'concerns will' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'earl from oklahoma' is the wordplay.
'earl' becomes 'e'.
'from' means one lot of letters go next to another.
'oklahoma' becomes 'state' (I can't explain this - if you can you should believe this answer much more).
'e'+'state'='ESTATE'
'and' is the link.
Can you help me to learn more?
(Other definitions for estate that I've seen before include "Housing area" , "Car with a rear door" , "Possessions at the time of death" , "Country property" , "Extent of one's property" .)