noun
island country; island nation
Refers to a sovereign state whose territory consists entirely of one or more islands. Often used in geopolitical or geographical contexts.
日本はアジアの島嶼国です。
Japan is an island country in Asia.
島嶼国は気候変動の影響を受けやすい。
Island nations are vulnerable to the effects of climate change.
島国 is the more common, everyday word for 'island country'. 島嶼国 is a formal, technical term often used in political or academic writing.
Compound of 島嶼 (とうしょ, 'islands') + 国 (こく, 'country'). 島嶼 is itself a compound of 島 (とう, 'island') and 嶼 (しょ, 'islet').