\Im*pen`e*tra*bil"i*ty\, n. [Cf. F.
imp['e]n['e]trabilit['e].]
1. Quality of being impenetrable.
2. (Physics) That property in virtue of which two portions of
   matter can not at the same time occupy the same portion of
   space.
3. Insusceptibility of intellectual or emotional impression;
   obtuseness; stupidity; coldness.