sarcasm vs trenchancy

sarcasm

noun
  • An act of sarcasm. 

  • 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. 

trenchancy

noun
  • Irony or bitterness of tone. 

  • The quality of being trenchant. 

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