Jane -, third wife of Henry VIII (7)
I believe the answer is:
seymour
This clue is a double definition.
'jane' is the first definition.
(Jane Seymour, third wife of Henry VIII)
'third wife of henry viii' is the second definition.
(I've seen this in another clue)
(Other definitions for seymour that I've seen before include "15 [JANE], one of the wives" , "See 15" , "Jane - - , Edward VI's mother" , "Jane -, third wife of Henry VIII" , "Henry VIII's wife Jane" .)