ennui vs torpor

ennui

noun
  • A gripping listlessness or melancholia caused by boredom; depression. 

verb
  • To make bored or listless; to weary. 

torpor

noun
  • A state of apathy or lethargy. 

  • A state similar to hibernation characterised by energy-conserving, very deep sleep. 

  • A state of being inactive or stuporous. 

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