Historical centre of holy study (5)
I believe the answer is:
'historical' is the definition.
Both the answer and definition are adjectives. Maybe they are linked in a way I don't understand?
'centre of holy study' is the wordplay.
'centre of' means to look at the middle letters.
'study' becomes 'den' (term for a study or office).
The centre of 'holy' is 'ol'.
Can you help me to learn more?
(Other definitions for olden that I've seen before include "Bygone" , "(Of days) in the long distant past!" , "Of a former age" , "Led on (anag)" , "of ancient history?" .)