mordancy vs sarcasm

mordancy

noun
  • The state or quality of being mordant. 

sarcasm

noun
  • Use of acerbic language to mock or convey contempt, often using irony and (in speech) often marked by overemphasis and a sneering tone of voice. 

  • An act of sarcasm. 

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