| 周密 | zhōu mì | careful / thorough / meticulous / dense / impenetrable | ![]() |
| 密不透风 | mì bù tòu fēng | sealed off / impenetrable | ![]() |
| 水泄不通 | shuǐ xiè - bù tōng | lit. not one drop can trickle through (idiom) / fig. (of crowds, traffic etc) impenetrable | ![]() |
| 水泄不通 | shuǐ xiè bù tōng | lit. not one drop can trickle through (idiom) / fig. impenetrable (crowd, traffic) | ![]() |
| 铜墙铁壁 | tóng qiáng tiě bì | copper wall, iron bastion (idiom) / impenetrable defense | ![]() |
| 高城深池 | gāo chéng shēn chí | high walls and deep moat (idiom) / impenetrable defense | ![]() |
| 弥蒙 | mí méng | impenetrable thick fog or smoke | ![]() |
