decedent vs lifeless

decedent

adj
  • Removing; departing; deceased. 

noun
  • A dead person. 

lifeless

adj
  • dead; having lost life 

  • inanimate; having no life 

  • dull or lacking vitality 

  • uninhabited, or incapable of supporting life 

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