graffiti vs splotch

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. 

splotch

verb
  • To mark with splotches. 

noun
  • An irregular-shaped spot or stain. 

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