noun
Teito Rapid Transit Authority subway; Eidan subway
Historical name for the subway lines formerly operated by the Teito Rapid Transit Authority (帝都高速度交通営団), commonly called Eidan. Now part of Tokyo Metro.
営団地下鉄は2004年に東京メトロに移行した。
The Eidan subway was transferred to Tokyo Metro in 2004.
The current operator of the former Eidan subway lines; 営団地下鉄 refers specifically to the pre-2004 entity.
Compound of 営団 (eidan, 'public corporation') and 地下鉄 (chikatetsu, 'subway'), referring to the Teito Rapid Transit Authority.