Added 9 October 2026 impregnability noun Categories: Describing WordsObscure Words noun ! Definition from WordNet 3.1, Princeton University. More about impregnability at Wordnik → Where our words come from → Having the strength to withstand attack. Related Words: invulnerabilityunimpugnabilityimperviabilityinvincibilityimperviousnessimpenetrabilityimperviablenessinviolabilityimpenetrablenessinvinciblenessinvulnerablenessinviolableness Back to today's word