crash pad vs room and board

crash pad

noun
  • Any place used for temporary lodging, especially without payment or permission. 

  • A room where one can recover after a bad acid trip. 

  • A protective foam pad placed on the ground, used as protection in case of falling from the wall. 

  • A place of temporary lodging for airline flight crews. 

room and board

noun
  • A place of lodging with daily meals, usually provided in return for rent or other considerations. 

How often have the words crash pad and room and board occurred in a corpus of books? (source: Google Ngram Viewer )