Special hat designed for eastern domains (10)
I believe the answer is:
caliphates
'eastern domains' is the definition.
The definition and answer can be both locations as well as being plural nouns.
Perhaps there's a link between them I don't understand?
'special hat designed' is the wordplay.
'designed' indicates an anagram (designed with the letters).
'special'+'hat'='specialhat'
'specialhat' anagrammed gives 'CALIPHATES'.
'for' acts as a link.
Can you help me to learn more?
(Another definition for caliphates that I've seen is " Offices for Middle Eastern rulers".)