billy vs kid leather

billy

noun
  • A billy goat. 

  • A good friend. 

  • A billy club. 

  • A male goat; a ram. 

  • A slubbing or roving machine. 

  • A bong for smoking marijuana. 

  • A tin with a swing handle used to boil tea over an open fire; a billycan; a billypot. 

  • A condom. 

kid leather

noun
  • Leather made from the skin of a young goat. 

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