A pair of bishops at scripture, one wearing a mitre perhaps (5)
I believe the answer is:
abbot
'one wearing a mitre perhaps' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'a pair of bishops at scripture' is the wordplay.
'pair of bishops' becomes 'BB' (abbreviation for bishop, written twice).
'at' is a charade indicator (letters next to each other).
'scripture' becomes 'OT' (Old Testament).
'a'+'bb'+'ot'='ABBOT'
Can you help me to learn more?
(Other definitions for abbot that I've seen before include "Head of monastery" , "Father" , "monastic leader" , "Chief monk" , "meeting Newton in Devon" .)