armor-plated vs pachydermatous

armor-plated

adj
  • Covered with a hard steel plate; especially of vehicles, boats, and defenses. 

pachydermatous

adj
  • Of or relating to the pachyderms. 

  • Like an elephant 

  • Thick-skinned; insensitive. 

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