Old Testament reflected by fellow empire (7)
I believe the answer is:
ottoman
'empire' is the definition.
(I've seen this before)
'old testament reflected by fellow' is the wordplay.
'old testament' becomes 'ot'.
'reflected by fellow' becomes 'toman' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'ot'+'toman'='OTTOMAN'
Can you help me to learn more?
(Other definitions for ottoman that I've seen before include "Armless, padded seat" , "Long cushioned seat with no back or arms" , "Turkish dynasty or long cushioned seat" , "Backless seat" , "that lacks arms and backing" .)