impenetrable
//ɪmˈpɛnɪtrəbəl//
Adjective
impenetrableCanonical form
more impenetrableComparative
most impenetrableSuperlative
1
Impossible to pass through or enter; completely resistant to penetration.
The castle was surrounded by an impenetrable wall.
2
Impossible to understand or comprehend; incomprehensible or inscrutable.
The professor's lecture was impenetrable to most of the students.
3
Not open to ideas, influences, or arguments; unyielding or closed-minded.
He remained impenetrable to all our suggestions for improvement.