excoriate vs graffiti

excoriate

verb
  • To wear off the skin of; to chafe or flay. 

  • To strongly denounce or censure. 

graffiti

verb
  • To mark a surface with such images. 

noun
  • Drawings or words drawn on a surface in a public place, usually made without authorization. 

  • Informal inscriptions, figure drawings, etc., as opposed to official inscriptions. 

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