铜墙铁壁 (tóng qiáng tiě bì) — impregnable fortress; fig. unassailable defense, invulnerable position
Definition
A chengyu (four-character idiom) literally 'copper walls and iron ramparts,' meaning an impregnable, unbreakable defense — used for both physical defenses and figurative strongholds like strategy, relationships, or barriers.
idiom
impregnable fortressfig. unassailable defenseinvulnerable position
Examples
- 铜墙铁壁，。Zhè zuò chéng shì de fáng yù xì tǒng yóu rú tóng qiáng tiě bì, dí rén wú fǎ gōng pò.This city's defense system is like an impregnable fortress that the enemy cannot break through.
- ，铜墙铁壁，。Zài tā de xīn lǐ, mǔ qīn de bǎo hù jiù shì tóng qiáng tiě bì, ràng tā gǎn dào ān quán.In his heart, his mother's protection is an unbreakable fortress that makes him feel safe.
- 铜墙铁壁，。Wǒ men gōng sī de jì shù bì lěi yǐ jīng xíng chéng le tóng qiáng tiě bì, jìng zhēng duì shǒu nán yǐ chāo yuè.Our company's technological barriers have formed an impregnable fortress that competitors can hardly surpass.
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