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.

Origin

Compound word
构词法gòucífǎ
联合liánhéSide by side

Two parts of equal weight, alike or opposite in meaning, standing side by side.

铜墙copper wall
铜tóngcopper墙qiángwall
偏正Modifier + head
铁壁iron wall
铁tiěiron壁bìwall
偏正Modifier + head

铜墙 means copper walls, 铁壁 means iron walls, together an impregnable defense.

Characters in this word

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

This origin belongs to the traditional form 銅; 铜 is its simplified writing.

Meaning part形符xíngfú
金金jīnmetal
Sound part声符shēngfú
同
同tóng銅tóng
Same sound today

The traditional form 銅 pairs 金 (metal) with 同 as the sound part; the simplified 铜 is a shorthand.

Open 铜 →

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

This origin belongs to the traditional form 牆; 墙 is its simplified writing.

Meaning part形符xíngfú
嗇嗇sèwheat in a granary
Sound part声符shēngfú
爿
爿pán牆qiáng
The sound has drifted apartThe sound part was a clue two thousand years ago — it often still helps, but not always.

In the traditional form 牆, 爿 gives the sound and 嗇, showing wheat in a granary, gives the wall meaning. The simplified 墙 is a later short form.

Open 墙 →

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

This origin belongs to the traditional form 鐵; 铁 is its simplified writing.

Meaning part形符xíngfú
金金jīnmetal
Sound part声符shēngfú
𢧤
𢧤𢧤鐵tiě
The sound has drifted apartThe sound part was a clue two thousand years ago — it often still helps, but not always.

The traditional form 鐵 pairs 金 (metal) with 𢧤 as a sound part; the simplified 铁 is a later shorthand.

Open 铁 →

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

Meaning part形符xíngfú
土土tǔearth
Sound part声符shēngfú
辟
辟pì壁bì
Same sound today

壁 combines 土 (earth) and 辟, which gives the sound. The whole means an earthen wall.

Open 壁 →

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