Imperviousness and Unyieldingness

Imperviousness noun - The quality of being impenetrable (by people or light or missiles etc.).

Unyieldingness and imperviousness are semantically related. In some cases you can use "Unyieldingness" instead a noun "Imperviousness".

Unyieldingness noun - Resoluteness by virtue of being unyielding and inflexible.

Imperviousness and unyieldingness are semantically related. Sometimes you can use "Imperviousness" instead a noun "Unyieldingness".