Search Result for "impregnability": 
Wordnet 3.0

NOUN (1)

1. having the strength to withstand attack;
[syn: invulnerability, impregnability]



The Collaborative International Dictionary of English v.0.48:

Impregnability \Im*preg`na*bil"i*ty\, n.
   The quality or state of being impregnable; invincibility.
   [1913 Webster]


WordNet (r) 3.0 (2006):

impregnability
    n 1: having the strength to withstand attack [syn:
         invulnerability, impregnability]