Definition
铜墙铁壁 is a four‑character idiom (成语) that literally means 'copper wall, iron fortress'. It is used figuratively to describe an extremely strong and impenetrable defense — whether physical (a fortification), organizational (a security system), or emotional (someone's protective shield). You will hear it in military, political, or business contexts to emphasize something that is nearly impossible to breach or defeat.
f.e.
impregnable fortressfig. unassailable defenseinvulnerable position
Examples
- 铜墙铁壁，。Zhè zuò chéngshì de fángyù xìtǒng yóurú tóng qiáng tiě bì, dírén wúfǎ gōngpò.This city's defense system is like an impregnable fortress that the enemy cannot break through.
- ，铜墙铁壁，。Zài tā de xīnli, mǔqīn de bǎohù jiùshì tóng qiáng tiě bì, ràng tā gǎndào ānquán.In his heart, his mother's protection is an unbreakable fortress that makes him feel safe.
- 铜墙铁壁，。Wǒmen gōngsī de jìshù bìlěi yǐjīng xíngchéng le tóng qiáng tiě bì, jìngzhēng duìshǒu nányǐ chāoyuè.Our company's technological barriers have formed an impregnable fortress that competitors can hardly surpass.
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