汤池金城 tāngchíjīnchéng strongly fortified 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金城 jīnchéng impregnable city an extremely strong or fortified city; literally a city of metal