'Impregnability' definitions:
Definition of 'impregnability'
From: WordNet
noun
Having the strength to withstand attack [syn: invulnerability, impregnability]
Definition of 'Impregnability'
From: GCIDE
- Impregnability \Im*preg`na*bil"i*ty\, n. The quality or state of being impregnable; invincibility. [1913 Webster]