noun. The quality or condition of being impenetrable.

noun. The inability of two bodies to occupy the same space at the same time.

noun. The character or condition of being impenetrable; incapability of being penetrated, in any sense of that word.

noun. In physics, specifically, that property of matter which prevents two bodies from occupying the same space at the same time; that property of matter by which it excludes all other matter from the space it occupies.

noun. Quality of being impenetrable.

noun. That property in virtue of which two portions of matter can not at the same time occupy the same portion of space.

noun. Insusceptibility of intellectual or emotional impression; obtuseness; stupidity; coldness.

noun. The characteristic of being impenetrable; invulnerability.

noun. the quality of being impenetrable (by people or light or missiles etc.)

noun. incomprehensibility by virtue of being too dense to understand

"` I meant by "impenetrability" that we've had enough of that subject, and it would be just as well if you'd mention what you mean to do next, as I suppose you don't mean to stop here all the rest of your life. '"

incomprehensibility  quality  

alkalinity  angularity  apartness  compactness  electronegativity  

coldness  obtuseness  stupidity