adj.
Pronunciation: im- ' preg-n ə -b ə l
Function: adjective
Etymology: Middle English imprenable, from Middle French, from in- + prenable vulnerable to capture, from prendre to take ― more at PRIZE
Date: 15th century
1 : incapable of being taken by assault : UNCONQUERABLE <an impregnable fortress>
2 : UNASSAILABLE also : IMPENETRABLE < impregnable walls>
– im · preg · na · bil · i · ty \ ( ˌ )im- ˌ preg-n ə - ' bi-l ə -t ē \ noun
– im · preg · na · ble · ness \ im- ' preg-n ə -b ə l-n ə s \ noun
– im · preg · na · bly \ -bl ē \ adverb