frivolous vs mundane

frivolous

adj
  • Silly, especially at an inappropriate time or in an inappropriate manner. 

  • Having no reasonable prospect of success because its claim is without merit, lacking a supporting legal or factual basis, while the filing party is, or should be, aware of this. 

  • Of little weight or importance; not worth notice; slight; trivial. 

mundane

adj
  • Tedious; repetitive and boring. 

  • Worldly, earthly, profane, vulgar as opposed to heavenly. 

  • Ordinary; not new. 

  • Pertaining to the Universe, cosmos or physical reality, as opposed to the spiritual world. 

noun
  • An unremarkable, ordinary human being. 

  • A person considered to be "normal", part of the mainstream culture, outside the subculture, not part of the elite group. 

  • The world outside fandom; the normal, mainstream world. 

  • A person who is not a Satanist. 

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