expiring vs moribund

expiring

adj
  • Ending, terminating, dying. 

moribund

adj
  • Approaching death; about to die; dying; expiring. 

  • Almost obsolete, nearing an end. 

noun
  • A person who is near to dying. 

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