impenetrable

impenetrable is an Adverb

Definition:

[1] Incapable of being penetrated or pierced; not admitting the passage of other bodies; not to be entered; impervious; as, an impenetrable shield. Highest woods impenetrable To star or sunlight. Milton.

[2] Having the property of preventing any other substance from occupying the same space at the same time.

[3] Inaccessible, as to knowledge, reason, sympathy, etc.; unimpressible; not to be moved by arguments or motives; as, an impenetrable mind, or heart. They will be credulous in all affairs of life, but impenetrable by a sermon of the gospel. Jer. Taylor.