銅
牆
鐵
壁
銅
牆
鐵
壁
Definitions4 characters , bastion (idiom); impenetrable defense
Usage•••frequent
Pronunciations
銅
牆
鐵
壁
As word
1copper wall, iron bastion (idiom); impenetrable defense
2copper wall, iron bastion (idiom); impenetrable defense
3copper wall, iron bastion (idiom); impenetrable defense
4copper wall, iron bastion (idiom); impenetrable defense