Impregnable (Adjective)
Meaning 1
Immune to attack; incapable of being tampered with; "an impregnable fortress"; "fortifications that made the frontier inviolable"; "a secure telephone connection".
Classification
All adjective clusters.
Synonyms
Related Words
Meaning 3
Incapable of being overcome, challenged or refuted; "an impregnable argument"; "impregnable self-confidence".
Classification
All adjective clusters.