The Hawkeye State (4)
I believe the answer is:
iowa
'the hawkeye state' is the definition.
('Iowa' can be a synonym of 'hawkeye state')
This is the entire clue.
(Other definitions for iowa that I've seen before include "'Hawkeye State'" , "American state, capital Des Moines" , "US state, capital Des Moines" , "US swing electoral state" , "part of United States" .)