汤池铁城 tāngchítiěchéng well-defended city Origin Definitions Defs Strokes Stroke Words Sentences Sents 汤池 湯池 tāngchí impenetrable moat (literary) A moat filled with boiling water, used as a metaphor for an extremely strong and impenetrable defense; often used in the idiom 金城汤池 jīnchéngtāngchí铁 鐵 tiě adjective firm firm; solid; hard; strong-willed城 chéng nounproper noun city wall city walls; defensive walls surrounding a town or area