cave vs crash pad

cave

noun
  • A storage cellar, especially for wine or cheese. 

  • A code cave. 

  • A hole, depression, or gap in earth or rock, whether natural or man-made. 

  • A large, naturally-occurring cavity formed underground or in the face of a cliff or a hillside. 

  • A shielded area where nuclear experiments can be carried out. 

  • A place of retreat, such as a man cave. 

  • A naturally-occurring cavity in bedrock which is large enough to be entered by an adult. 

  • Debris, particularly broken rock, which falls into a drill hole and interferes with drilling. 

  • A group that breaks from a larger political party or faction on a particular issue. 

  • A collapse or cave-in. 

  • The vagina. 

intj
  • look out!; beware! 

verb
  • To engage in the recreational exploration of caves. 

  • To hollow out or undermine. 

  • To surrender. 

  • In room-and-pillar mining, to extract a deposit of rock by breaking down a pillar which had been holding it in place. 

  • To collapse. 

crash pad

noun
  • 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. 

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

  • A place of temporary lodging for airline flight crews. 

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