形容词
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.
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.
1. incapable of being overcome, challenged or refuted
e.g. an impregnable argument
impregnable self-confidence
Synonym: inexpugnable
2. capable of conceiving
Synonym: conceptive
3. immune to attack
incapable of being tampered with
e.g. an impregnable fortress
fortifications that made the frontier inviolable
a secure telephone connection