coma vs lethargy

coma

noun
  • A state of unconsciousness from which one may not wake up, usually induced by some form of trauma. 

  • A tuft or bunch, such as the assemblage of branches forming the head of a tree, a cluster of bracts when empty and terminating the inflorescence of a plant, or a tuft of long hairs on certain seeds. 

  • A cloud of dust surrounding the nucleus of a comet. 

  • A defect characterized by diffuse, pear-shaped images that in an ideal image would appear as points. 

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. 

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