Assyrian capital (7)
I believe the answer is:
nineveh
'assyrian capital' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for nineveh that I've seen before include "Ancient Assyrian capital" , "Assyrian capital; Jonah preached against it" , "Ancient capital of Assyria" , "Biblical city" , "old city" .)