South-Eastern Asia

… However, the term South-East Asia was not unheard of in English until then. It has been reported that the expression South-Eastern Asia was already in use in the title of a travelogue in 1839, although the form was slightly different. However, the meaning differs in that it only refers to the part of South-East Asia used today, that is, the mainland of Southeast Asia, and does not include the islands. …

*Some of the terminology that refers to "South-Eastern Asia" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…　もっともSouth‐East Asiaという言葉が，それまでの英語になかったわけではない。やや形は異なるが，South‐Eastern Asiaという表現は，すでに1839年にある旅行記の表題に用いられていた事実が報告されている。ただその意味は現在用いられるSouth‐East Asiaの一部，すなわち東南アジア大陸部のみを指し，島嶼部は含まない点に相違がみられる。…

※「South-Eastern Asia」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報