<p><strong>Adjective:</strong></p><ul><li>incapable of being investigated, analyzed, or scrutinized; impenetrable.</li><li>Synonyms: undiscoverable, inexplicable, incomprehensible, hidden.</li><li>Antonyms: comprehensible.</li><li>not easily understood; mysterious; unfathomable: an inscrutable smile.</li><li>incapable of being seen through physically; physically impenetrable: the inscrutable depths of the ocean.</li></ul>