lethargy vs sharpness

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. 

sharpness

noun
  • acuteness or acuity. 

  • the fineness of the point a pointed object. 

  • pungency or acidity. 

  • the cutting ability of an edge; keenness. 

  • The product or result of being sharp. 

  • distinctness, focus. 

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