abstruseness vs sphinx

abstruseness

noun
  • The property of being abstruse; abstrusity. 

sphinx

noun
  • A person who keeps his/her thoughts and intentions secret; an enigmatic or impassive person. 

  • A sphinx moth. 

  • A sphincter. 

  • A creature with the head of a person and the body of an animal (commonly a lion). 

verb
  • To adopt the posture of the Sphinx. 

  • To decorate with sphinxes. 

  • To be inscrutable, often through silence. 

  • To behave in a manner characteristic of the Sphinx. 

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