Two boys, a state (9)
I believe the answer is:
louisiana
'state' is the definition.
(I know that Louisiana is a state)
'two boys a' is the wordplay.
'two boys' can mean two replacements for 'boy'.
'boy' becomes 'louis' ().
'boy' becomes 'ian' (man's name).
'louis'+'ian'+'a'='LOUISIANA'
(Other definitions for louisiana that I've seen before include "US southern state" , "US state, capital Baton Rouge" , "IOU a snail over in the US state" , "State named for French king" , "Southern United State on the Gulf of Mexico" .)