noun
East Asian countries
A formal, somewhat dated term referring collectively to the nations of East Asia. In modern contexts, 東アジア諸国 is more common.
東亜諸国との経済協力が重要だ。
Economic cooperation with East Asian countries is important.
More common modern term for East Asian countries; 東亜諸国 is a formal, slightly old-fashioned equivalent.
Compound of 東亜 (East Asia) and 諸国 (various countries). 東亜 is a Sino-Japanese term for East Asia, now largely replaced by 東アジア in everyday usage.