columbarium

noun4

1. •
   A building, a vault or a similar place for the respectful and usually public storage of cinerary urns containing cremated remains.

   • The columbarium (vaults lined with recesses for cinerary urns) in the form of a grotto (a cave-like structure) is the centerpiece of the Elks plot. — 2004
2. •
   A niche in such a building for housing urns.
3. •
   (historical) A columbary, especially a large and architecturally impressive one for housing a large colony of pigeons or doves, such as those in ancien régime France.

   • Doves were culticly protected; great towers were built for them in which they could nest; they were called columbaria (columba is the Latin word for dove). — 1979
4. •
   A pigeonhole in such a dovecote.