impregnable
im preg nuh buhl
- s immune to attack; incapable of being tampered with
an impregnable fortress - s capable of conceiving
- s incapable of being overcome, challenged or refuted
an impregnable argument
impregnable self-confidence
- It recounts the story of the ancient impregnable city that was destroyed partly by its overreaching.
- His commander adopted the scheme, and Scruggs had his first taste of plotting to crack defenses that had been thought to be impregnable.
- Bush's argument is tight, concise and, so far, impregnable.