n. An underground system of tunnels and chambers with recesses for graves, used (in former times) as a cemetery; a subterranean tunnel system used for burying the dead, as in Paris or ancient Rome.
the GNU version of the Collaborative International Dictionary of English
n. A cave, grotto, or subterraneous place of large extent used for the burial of the dead; -- commonly in the plural.
The Century Dictionary and Cyclopedia
n. Originally, the name of a locality near Rome, the “Hollows,” in which the church of St. Sebastian, with extensive burial-vaults, was built; but afterward applied to the vaults themselves, and to similar underground burial-places.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. an underground tunnel with recesses where bodies were buried (as in ancient Rome)
Word Usage
"The term catacomb was applied to these subterranean cemeteries at a much later period."