monomaniacal vs obstinate

monomaniacal

adj
  • Fanatical, or obsessed with one cause or idea to the exclusion of other concerns. 

  • Of or relating to a monomaniac. 

obstinate

adj
  • Stubbornly adhering to an opinion, purpose, or course, usually with implied unreasonableness; persistent. 

  • Typical of an obstinate person; fixed and unmoving. 

  • Not easily subdued or removed. 

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