crypt vs tomb

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. 

tomb

noun
  • A small building (or "vault") for the remains of the dead, with walls, a roof, and (if it is to be used for more than one corpse) a door. It may be partly or wholly in the ground (except for its entrance) in a cemetery, or it may be inside a church proper or in its crypt. Single tombs may be permanently sealed; those for families (or other groups) have doors for access whenever needed. 

  • A pit in which the dead body of a human being is deposited; a grave. 

  • One who keeps secrets. 

verb
  • To bury. 

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