frivolous vs reverent

frivolous

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

  • 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. 

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

reverent

adj
  • Showing or characterized by great respect or reverence; respectful. 

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