Impregnable
Impregnable , adjective
[French imprenable; pref. im- not + prenable pregnable, from prendre to take, Latin prehendere. See Comprehend, Get to obtain.]
Not to be stormed, or taken by assault; incapable of being subdued; able to resist attack; unconquerable; as, an impregnable fortress; impregnable virtue.
The man's affection remains wholly unconcerned and impregnable.
Impregnable , adjective
[See Impregnate.]
(Biology) Capable of being impregnated, as the egg of an animal, or the ovule of a plant.