Tehran's country (4)
I believe the answer is:
iran
'tehran's country' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for iran that I've seen before include "Country where ayatollahs replaced a shah" , "Modern-day Persia" , "Persia some time ago" , "Nation" , "Iraq's neighbour" .)