pigmentation vs pock

pigmentation

noun
  • Coloration of human, plant or animal tissue, especially by pigment. 

pock

noun
  • A pus-filled swelling on the surface on the skin caused by an eruptive disease. 

  • Any pit, especially one formed as a scar 

verb
  • To scar or mark with pits 

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