金城鉄壁 きんじょうてっぺき Meanings Noun impregnable castle (walls) の-adjective impregnable; invulnerable; unassailable Kanji 金 money. Read as キン. 城 castle. Read as ジョウ. 鉄 iron. Read as テツ. 壁 wall. Read as ヘキ. Word lists Yojijukugo (四字熟語) Jinuma: Japanese Dictionary · Word lists