brooding vs rueful

brooding

adj
  • Deeply or seriously thoughtful. 

  • Broody; incubating eggs by sitting on them. 

noun
  • A spell of brooding; the time when someone broods. 

rueful

adj
  • Inspiring pity or compassion. 

  • Bad; woeful; deplorable. 

  • Causing, feeling, or expressing regret or sorrow, especially in a wry or humorous way. 

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