鉄てっ壁ぺきTop 35000MeaningsNoun1. iron wall; impregnable fortressNo-adjective2. impregnable; invulnerable; unassailable; cast-ironKanji used鉄iron壁wallPitch accentてっぺきUsed in vocabulary金きん城じょう鉄てっ壁ぺきimpregnable castle (walls); impregnable; invulnerable; unassailableNoun