Tom and Anna agitated, in a state (7)
I believe the answer is:
montana
'state' is the definition.
(state of the US)
'tom and anna agitated' is the wordplay.
'and' means one lot of letters go next to another.
'agitated' indicates anagramming the letters.
'tom'+'anna'='tomanna'
'tomanna' with letters rearranged gives 'MONTANA'.
'in a' acts as a link.
(Other definitions for montana that I've seen before include "Nato man (anag) - US state" , "One US state ..." , "The "Big Sky State"" , "Send manna to this US state" , "North-western state bordering Canada" .)