billfold vs leather

billfold

noun
  • A small, folding sleeve or case designed to hold paper currency, as well as credit cards, pictures, etc. 

leather

noun
  • A piece of the above used for polishing. 

  • A punch. 

  • A tough material produced from the skin of animals, by tanning or similar process, used e.g. for clothing. 

  • A cricket ball or football. 

  • A good defensive play 

  • clothing made from the skin of animals, often worn by motorcycle riders. 

verb
  • To cover with leather. 

  • To spank or beat with a leather belt or strap. 

  • To strike forcefully. 

adj
  • Made of leather. 

  • Referring to one who wears leather clothing (motorcycle jacket, chaps over 501 jeans, boots), especially as a sign of sadomasochistic homosexuality. 

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