noun
constituent country; constituent nation
Refers to a country that is part of a larger political entity, such as the UK's constituent countries or the countries within the Kingdom of the Netherlands.
イギリスは四つの構成国から成る。
The United Kingdom consists of four constituent countries.
オランダ王国の構成国には、オランダ本
The constituent countries of the Kingdom of the Netherlands include, besides the Netherlands proper, Aruba and Curaçao.