Word Definition

Impenetrable

  1. Having the property of preventing any other substance from occupying the same space at the same time.
  2. Inaccessible, as to knowledge, reason, sympathy, etc.; unimpressible; not to be moved by arguments or motives; as, an impenetrable mind, or heart.
  3. Incapable of being penetrated or pierced; not admitting the passage of other bodies; not to be entered; impervious; as, an impenetrable shield.