Book set in US city or miserable, dark state (9)
I believe the answer is:
obscurity
'state' is the definition.
(obscurity is a kind of state)
'book set in us city or miserable dark' is the wordplay.
I cannot really see how this works, but
'book' could be 'b' (abbreviation for book) and 'b' is located in the answer.
'city' could be 'ur' (ancient Sumerian city state) and 'ur' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for obscurity that I've seen before include "Gloominess" , "Vagueness" , "Inconspicuousness" , "Lack of clarity" , "Absence of fame" .)