insincere vs solemn

insincere

adj
  • Not genuinely meaning what has been expressed; not sincere; artificial. 

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 insincere and solemn occurred in a corpus of books? (source: Google Ngram Viewer )