impervious

This term describes a state of total resistance, whether physical or psychological. In a material sense, it suggests a hard, sealed barrier that prevents penetration, often used in technical or industrial contexts to describe waterproof membranes or protective coatings.

When applied to human personality or emotion, it conveys a sense of stoicism or stubbornness. It implies a psychological shield that renders a person immune to outside influence, such as insults or persuasion, often suggesting a coldness or an impenetrable level of confidence.