digression vs veering

digression

noun
  • An elongation, a deflection or deviation from a mean position or expected path. 

  • An aside, an act of straying from the main subject in speech or writing. 

  • The act of straying from the main subject in speech or writing, (rhetoric) particularly for rhetorical effect. 

veering

noun
  • A motion that veers; a sudden swerve. 

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