Alternatively gone off in a state (6)
I believe the answer is:
oregon
'a state' is the definition.
(I know that Oregon is a state)
'alternatively gone off in' is the wordplay.
'alternatively' becomes 'or' ().
'off' is an anagram indicator.
'in' is an insertion indicator.
'gone' anagrammed gives 'egon'.
'or' put within 'egon' is 'OREGON'.
(Other definitions for oregon that I've seen before include "US north-western coastal state" , "W. coast US state" , "Salem is this State's capital" , "State of north-west US" , "area of the US" .)