cross-purpose vs unintelligibility

cross-purpose

noun
  • A contrary or conflicting purpose or understanding, especially an unintentional or misconceived one. 

unintelligibility

noun
  • The quality or condition of being unintelligible. 

  • Something that is unintelligible. 

How often have the words cross-purpose and unintelligibility occurred in a corpus of books? (source: Google Ngram Viewer )