furlough vs laissez-passer

furlough

noun
  • The documents authorizing such leave. 

  • A period of unpaid time off, used by an employer to reduce costs. 

  • especially one granted to a member of the armed forces, or to a prisoner. 

  • especially one granted to a missionary. 

verb
  • To grant a furlough to (someone). 

  • To have (an employee) not work in order to reduce costs; to send (someone) on furlough. 

laissez-passer

noun
  • A pass or permit; a document permitting the bearer to travel, sometimes issued as an emergency passport. 

How often have the words furlough and laissez-passer occurred in a corpus of books? (source: Google Ngram Viewer )