contumacious vs mulish

contumacious

adj
  • Contemptuous of authority; willfully disobedient; rebellious. 

  • Willfully disobedient to the summons or orders of a court. 

mulish

adj
  • Characteristic of a mule; stubborn, obstinate, or intractable 

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