impenetrable
Pronunciation:
/ɪmˈpɛnətɹəbəl/adjective
Definitions
Not penetrable.
Example: The fortress is impenetrable, so it cannot be taken.
Incomprehensible; fathomless; inscrutable.
Example: Business jargon makes this document impenetrable, I can't understand it.
Opaque; obscure; not translucent or transparent.
Example: When night falls, she cloaks the world in impenetrable darkness.