languor vs melancholy

languor

noun
  • Melancholy caused by lovesickness, sadness, etc.; (countable) an instance of this. 

  • A state of the body or mind caused by exhaustion or disease and characterized by a languid or weary feeling; lassitude; (countable) an instance of this. 

  • Dullness, sluggishness; lack of vigour; stagnation. 

  • Listless indolence or inactivity, especially if enjoyable or relaxing; dreaminess; (countable) an instance of this. 

  • Heavy humidity and stillness of the air. 

verb
  • To languish. 

melancholy

noun
  • Great sadness or depression, especially of a thoughtful or introspective nature. 

  • Black bile, formerly thought to be one of the four "cardinal humours" of animal bodies. 

adj
  • Affected with great sadness or depression. 

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