cavern vs crypt

cavern

noun
  • An underground chamber. 

  • A large, dark place or space. 

  • A large cave. 

verb
  • To put into a cavern. 

  • To form a cavern or deep depression in. 

crypt

noun
  • An underground vault, especially one beneath a church that is used as a burial place. 

  • Any of the genus Cryptopus of orchids of Madagascar and Mauritius. 

  • A small pit or cavity in the surface of an organ or other structure. 

  • Any of the genus Cryptocoryne of aquatic plants of southern and southeastern Asia. 

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