circumstantial vs straight from horse’s mouth

circumstantial

adj
  • Pertaining to or dependent on circumstances, especially as opposed to essentials; incidental, not essential. 

  • Suggesting guilt, but not proving it conclusively. 

  • Abounding with minor circumstances; in great detail; particular. 

  • Full of circumstance or pomp; ceremonial. 

noun
  • Something incidental to the main subject, but of less importance. 

straight from horse’s mouth

How often have the words circumstantial and straight from horse’s mouth occurred in a corpus of books? (source: Google Ngram Viewer )