関東

Short for 関東地方 (Kantō-chihō): A geographical region in eastern Japan that includes the capital city of Tokyo and surrounding prefectures

(historical) the area east of 逢坂の関 (Ōsaka-no-seki, “tollgate of Ōsaka-yama”) or later, east of 箱根の関 (Hakone-no-seki, “tollgate of Mount Hakone”)

(archaic) the area to the east of 函谷関 (Kankoku-kan, “Hangu Pass”)

(archaic) the area to the east of 山海関 (Sankai-kan, “Shanhai Pass”)

a surname