Shah's domain, once (4)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">shah's domain once</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for iran that I've seen before include "It used to be Persia" , "Country lying to south of Caspian sea" , "Nation" , "Tehran's country" , "Country where ayatollahs replaced a shah" .)