dullness vs idleness

dullness

noun
  • The quality of being uninteresting; boring; humorless or irksome. 

  • The quality of not perceiving or kenning things distinctly. 

  • The quality of being slow of understanding things; stupidity. 

  • Lack of interest or excitement. 

  • The lack of visual brilliance; want of sheen. 

  • bluntness. 

idleness

noun
  • Groundlessness; worthlessness; triviality; vanity; frivolity. 

  • The state of being idle; inactivity. 

  • The state of being indolent; indolence. 

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