If you describe a building or other place as impregnable, you mean that it cannot be broken into or captured.
例句
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。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。
ADJ
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.
例句
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。
英汉词典释义
adj.
攻不破的, 坚不可摧的
an impregnable castle攻不破的堡垒The lofty walls of the castle seemed impregnable.这座城堡的高墙似乎坚不可摧。They will establish impregnable fortresses.他们将建造坚不可摧的城堡。
英英词典释义
Adjective
1. able to withstand attack;
"an impregnable fortress""fortifications that made the frontier inviolable"