National history, perhaps (7)
I believe the answer is:
subject
I believe this is a double definition.
'national' is the first definition.
(synonyms)
'history perhaps' is the second definition.
(history is a kind of subject)
(Other definitions for subject that I've seen before include "School topic" , "Musical theme" , "Expose; field of study" , "Theme (of a fugue)" , "In school possibly English" .)