furlough vs shore leave

furlough

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

  • The documents authorizing such leave. 

  • 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. 

shore leave

noun
  • Free time given to sailors of the military navy when they are off duty and allowed to disembark and spend time on land. 

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