comprehension vs hitting it off

comprehension

noun
  • The inclusion of nonconformists within the Church of England. 

  • Thorough understanding. 

  • The totality of intensions, that is, attributes, characters, marks, properties, or qualities, that the object possesses, or else the totality of intensions that are pertinent to the context of a given discussion. 

  • A compact syntax for generating a list in some functional programming languages. 

hitting it off

How often have the words comprehension and hitting it off occurred in a corpus of books? (source: Google Ngram Viewer )