adust vs mournful

adust

adj
  • Hot and dry; thirsty or parched. 

  • Of a bodily humour: abnormally dark or over-concentrated (associated with various states of discomfort or illness, specifically being too hot or dry). 

mournful

adj
  • Fit to inspire mourning; tragic. 

  • Filled with grief or sadness; being in a state in which one mourns. 

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