East Asia; the Orient
Refers to the geographical and cultural region of East Asia. 'The Orient' is an older, sometimes literary translation, but 'East Asia' is the primary modern meaning.
東亜の国々は経済的に結びついている。
The countries of East Asia are economically interconnected.
彼は東亜の歴史を研究している。
He is researching the history of East Asia.
東亜 refers to East Asia (China, Japan, Korea, etc.), while 東南アジア refers to the distinct region of Southeast Asia (Vietnam, Thailand, Indonesia, etc.), so the two are easily confused by their similar names but denote different areas.
Standard modern kanji spelling for East Asia.
Outdated kanji form using 亞 instead of 亜; still encountered in historical texts.
Compound of 東 (east) and 亜 (Asia, originally an abbreviation for 亜細亜). The term was coined in Japan during the Meiji era as a translation of 'East Asia'.