from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. the state of being impervious
from The Century Dictionary and Cyclopedia
- n. The state or quality of being impervious.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the quality of being impenetrable (by people or light or missiles etc.)
impervious + -ness (Wiktionary)