pejoration vs putrefaction

pejoration

noun
  • The act or process of becoming worse; worsening or degeneration. 

  • The process by which a word acquires a more negative meaning over time. 

putrefaction

noun
  • The state of being rotten. 

  • The act of causing to rot; the anaerobic splitting of proteins by bacteria and fungi with the formation of malodorous, incompletely oxidized products. 

  • Rotten material. 

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