Which word best describes something that is "impervious"?

The word "impervious" refers to a state of being unaffected, or not allowing something to pass through or be impacted by certain forces or influences. Therefore, the definition that aligns perfectly with the meaning of "impervious" is "Not affected or hurt by." This reflects its use in contexts such as describing materials that do not allow water to penetrate or individuals who remain unbothered by external pressures or criticisms.

In contrast, the other choices present meanings opposite or unrelated to "impervious." For example, "easily penetrable" and "able to be damaged easily" imply a vulnerability that contradicts the concept of being impervious. Lastly, "open to all influences" suggests a receptiveness that negates the resistance inherent in the term "impervious."