Assyrian foe (4)
I believe the answer is:
mede
'assyrian foe' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for mede that I've seen before include "One of the old people" , "One of the old folk" , "Lawmaker" , "Old Indo-European" , "Ancient native of Persia" .)