Northernmost US state (6)
I believe the answer is:
alaska
'northernmost us state' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for alaska that I've seen before include "Most northerly state of America" , "NW US state" , "49th US state" , "Most northerly state of USA" , "that may be baked? Not by the sun" .)