catacomb

 
Pronunciation: /ˈkatəkuːm, -kəʊm/

noun

(usually catacombs)
  • an underground cemetery consisting of a subterranean gallery with recesses for tombs, as constructed by the ancient Romans.
  • an underground construction resembling or compared to catacombs.

Origin:

Old English, from late Latin catacumbas, the name of the subterranean cemetery of St Sebastian near Rome