固ㄍㄨˋgù若ㄖㄨㄛˋruò金ㄐㄧㄣjīn湯ㄊㄤtāng

  1. 比喻防守嚴密，無懈可擊。參見「金城湯池」條。似堅如磐石﹑穩如泰山反土崩瓦解﹑一觸即潰﹑危如累卵

英secure as a city protected by a wall of metal and a moat of boiling water (idiom)​, well fortified, invulnerable to attack