Naiveté shown at bar in Orange County by old US vice-president, losing the head (9)
I believe the answer is:
'naivete' is the definition.
(I know that innocence is a type of naivete)
'at bar in orange county by old us vice-president losing the head' is the wordplay.
'at' says to put letters next to each other.
'bar' becomes 'inn' (both can mean a drinking establishment).
'in orange county by old us' becomes 'oc' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'vice-president' becomes 'Pence' (Mike Pence).
'losing the head' means to remove the first letter.
'pence' with its initial letter removed is 'ence'.
'inn' next to 'oc' is 'innoc'.
'shown' is the link.
Can you help me to learn more?
(Other definitions for innocence that I've seen before include "Uncorrupted state" , "subject of Blake's songs" , "Freedom from guilt" , "Moral purity" , "Lack of guilt" .)