Origin: Latin suffix -able
Impregnable has 5 different meanings across 1 category:
immune to attack; incapable of being tampered with
"an impregnable fortress"
"fortifications that made the frontier inviolable"
"a secure telephone connection"
capable of conceiving
incapable of being overcome, challenged or refuted
"an impregnable argument"
"impregnable self-confidence"
Too strong to be penetrated.
Capable of being impregnated.