discourteous vs pachydermatous

discourteous

adj
  • impolite; lacking consideration for others 

pachydermatous

adj
  • Thick-skinned; insensitive. 

  • Of or relating to the pachyderms. 

  • Like an elephant 

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