noun
emirate; sheikdom
A political territory ruled by an emir or sheik; commonly used in reference to the United Arab Emirates (アラブ首長国連邦).
アラブ首長国連邦は七つの首長国から成る。
The United Arab Emirates consists of seven emirates.
首長 is the ruler (emir, sheik, or chief), while 首長国 is the territory they rule.
Compound of 首長 (shuchō, 'chief, emir') + 国 (koku, 'country'). The term is a modern coinage used to translate 'emirate'.