The meaning of IMPENETRABLE is incapable of being penetrated or pierced. How to use impenetrable in a sentence.

IMPENETRABLE definition: 1. impossible to see through or go through: 2. impossible to understand: 3. impossible to see…. Learn more.

1. Impossible to penetrate or enter: an impenetrable fortress. 2. Impossible to understand; incomprehensible: impenetrable jargon. 3. Impervious to sentiment or argument: an impenetrable heart.

Definition of impenetrable adjective in Oxford Advanced American Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

Impenetrable definition: Impossible to penetrate or enter.

IMPENETRABLE definition: not penetrable; that cannot be penetrated, pierced, entered, etc. See examples of impenetrable used in a sentence.

that cannot be penetrated: an impenetrable barrier. that cannot be understood: an impenetrable mystery. unfathomable: an impenetrable mystery. Physics possessing impenetrability. Latin impenetrābilis. …

If you describe something such as a book or a theory as impenetrable, you are emphasizing that it is impossible or very difficult to understand.

Factsheet What does the adjective impenetrable mean? There are five meanings listed in OED's entry for the adjective impenetrable. See ‘Meaning & use’ for definitions, usage, and quotation evidence.

Dec 14, 2025 · Noun impenetrable (plural impenetrables) A person not openly given to friendship. (clarification of this definition is needed.)