impenetrable vs unsociable

impenetrable

noun
  • A person not openly given to friendship. 

adj
  • Opaque; obscure; not translucent or transparent. 

  • Not penetrable. 

  • Incomprehensible; fathomless; inscrutable. 

unsociable

noun
  • A person who is not sociable. 

adj
  • not congenial or compatible 

  • not desiring the company of others 

  • unfriendly 

How often have the words impenetrable and unsociable occurred in a corpus of books? (source: Google Ngram Viewer )