lethargy vs toil

lethargy

noun
  • A condition characterized by extreme fatigue or drowsiness, deep unresponsiveness, or prolonged sleep patterns. 

  • A state of extreme torpor or apathy, especially with lack of emotion, energy or enthusiasm; (loosely) sluggishness, laziness. 

toil

verb
  • To struggle. 

  • To labour; work. 

  • To weary through excessive labour. 

  • To work (something); often with out. 

noun
  • Trouble, strife. 

  • Labour, work, especially of a grueling nature. 

  • A net or snare; any thread, web, or string spread for taking prey. 

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