Tennessee claiming state inn (6)
I believe the answer is:
tavern
'inn' is the definition.
(I've seen this before)
'tennessee claiming state' is the wordplay.
'tennessee' becomes 'TN' (abbreviation for the US state).
'claiming' is an insertion indicator.
'state' becomes 'aver' (both can mean to declare).
'tn' enclosing 'aver' is 'TAVERN'.
(Other definitions for tavern that I've seen before include "An old inn or hostelry" , "Building with a bar" , "An old inn, musically in the town" , "An old English pub" , "Tap house" .)