catacomb vs mortuary

catacomb

noun
  • An underground system of tunnels and chambers with recesses for graves, used (in former times) as a cemetery; a tunnel system used for burying the dead, as in Paris or Ancient Rome. 

mortuary

noun
  • A place where dead bodies are stored prior to burial or cremation. 

  • A sort of ecclesiastical heriot, a customary gift claimed by, and due to, the minister of a parish on the death of a parishioner. 

adj
  • Of, or relating to death or a funeral; funereal. 

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