Tehran's land (4)
I believe the answer is:
iran
'tehran's land' 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 "Persia today" , "Country of western Asia" , "Persia some time ago" , "Modern name for Persia" , "It was known as Persia until 1935" .)