US state; capital Juneau (6)
I believe the answer is:
alaska
This clue is a double definition.
'us state' is the first definition.
(I've seen this before)
'capital juneau' is the second definition.
(I know that Alaska has the capital city Juneau)
(Other definitions for alaska that I've seen before include "Anchorage is the capital" , "Cold US state" , "Most northerly US state" , "Anchorage location" , "State of north-west US" .)