seclusion vs secretness

seclusion

noun
  • The act of secluding, shutting out or keeping apart. 

  • A secluded, isolated or private place. 

  • The mature phase of the extratropical cyclone life cycle. 

  • The state of being secluded or shut out, as from company, society, the world, etc.; solitude. 

secretness

noun
  • Quality of being secret. 

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