frivolous vs solemn

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. 

solemn

adj
  • Characterized by or performed with appropriate or great ceremony or formality. 

  • Of or pertaining to religious ceremonies and rites; (generally) religious in nature; sacred. 

  • Inspiring serious feelings or thoughts; sombrely impressive. 

  • Deeply serious and sombre; grave. 

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