東とう夷い西せい戎じゅう

Meanings

1

barbarians to the east and west

yojijukugo (four-character idiom)

Historical term from the perspective of ancient China, referring to non-Chinese peoples on the eastern and western borders. Used as a yojijukugo.

「東とう夷い西せい戎じゅう」は、古こ代だい中ちゅう国ごくで周しゅう辺へんの異い民みん族ぞくを指さした言こと葉ばだ。
"Tōi Seijū" is a term that referred to surrounding non-Chinese peoples in ancient China.