Dictionary and Thesaurus

Definition of Impenetrable

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

Synonyms of Impenetrable

• Dense
• Heavy

Antonyms of Impenetrable

• Penetrable

Homophones of Impenetrable