1. 牢不可破的;固若金汤的;无法攻取的
If you describe a building or other place as impregnable, you mean that it cannot be broken into or captured.
e.g. The old Dutch fort with its thick high walls looks virtually impregnable...
古老的荷兰城堡城墙又厚又高,看起来几乎固若金汤。
e.g. In those impregnable mountains, the guerrillas could hold out for years.
在那些易守难攻的大山里,游击队可以坚持很多年。
2. 不可战胜的;不可撼动的
If you say that a person or group is impregnable, or their position is impregnable, you think they cannot be defeated by anyone.
impregnable的解释
e.g. The Bundesbank's seemingly impregnable position has begun to weaken.
德意志联邦银行看似不可撼动的地位开始削弱了。