mouldy vs rueful

mouldy

adj
  • Worthless; lousy; rotten. 

  • Covered with mould. 

  • Showing signs of neglect; disused. 

rueful

adj
  • Bad; woeful; deplorable. 

  • Inspiring pity or compassion. 

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

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