impregnable meaning and definition

IMPREGNABLE adjective

Definition of impregnable (adjective)

1. immune to attack; incapable of being tampered with
   • "an impregnable fortress"; "fortifications that made the frontier inviolable"; "a secure telephone connection"
   • synonyms: inviolable, secure, strong, unassailable, unattackable
2. capable of conceiving
   • synonyms: conceptive
3. incapable of being overcome, challenged or refuted
   • "an impregnable argument"; "impregnable self-confidence"
   • synonyms: inexpugnable