boneyard vs catacomb

boneyard

noun
  • A graveyard. 

  • A dumpsite for obsolete or unusable aircraft. 

  • In the game of dominoes, the pile of upside-down pieces that have yet to be used. 

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. 

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