concealment vs solitude

concealment

noun
  • The condition of being hidden or concealed. 

  • The practice of keeping secrets. 

  • protection from observation or surveillance. 

solitude

noun
  • Aloneness; the state of being alone, solitary, or by oneself. 

  • A lonely or deserted place. 

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