What is the meaning of 蝦夷?

Emishi (ancient ethnic group living in eastern Japan)

those people living in the northeast of Japan, regardless of ethnicity, with customs and culture and government that differ from the central Japanese imperial state

an ancient ethnic group that once lived in what is now the 関東 (Kantō), 北陸 (Hokuriku) and 東北 (Tōhoku) regions, likely as far as Hokkaido; likely related to the Ainu people

short for 蝦夷松 (Ezo matsu): Yezo spruce (Picea jezoensis)

short for 蝦夷地 (Ezochi): collective name for Hokkaido (mostly), the Kuril Islands, and Sakhalin before the Meiji period

an ancient ethnic group that once lived on what is now the 関東 (Kantō), 北陸 (Hokuriku) and 東北 (Tōhoku) regions, likely as far as Hokkaido; likely related to the Ainu people

short for 蘇我蝦夷 (Soga no Emishi): Asuka-period statesman of the Yamato court, son of Soga no Umako and father of Soga no Iruka

an ancient ethnic group that once lived on what is now the 関東 (Kantō), 北陸 (Hokuriku) and 東北 (Tōhoku) regions, likely as far as Hokkaido; likely related to the Ainu people

an ancient ethnic group that once lived on what is now the 関東 (Kantō), 北陸 (Hokuriku) and 東北 (Tōhoku) regions, likely as far as Hokkaido; likely related to the Ainu people

an ancient ethnic group that once lived on eastern and northeastern Japan and was possibly related to the Ainu people

Source: wiktionary.org