chantage vs milking

chantage

noun
  • blackmail; the extortion of money by threats of scandalous revelations 

milking

noun
  • The act by which any animal is milked. 

  • Male masturbation (or fellatio) that leads to the release of semen, especially when performed on a milking table. 

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