What do we call a receptacle for communal placement of cremated and/or skeletal remains?

The term used to describe a receptacle for communal placement of cremated and/or skeletal remains is "ossuary." An ossuary is specifically designed to hold human skeletal remains and can serve as a burial site for multiple people. It is often used when burial space is limited or when there are cultural practices that favor the consolidation of remains.

This term comes from the Latin word "ossa," meaning bones. Ossuaries can take various forms, from simple containers to elaborate structures, and they serve both functional and commemorative purposes in many cultures. In contrast, a tomb typically serves as a burial place for one or more individuals and may not be specifically designed for cremated remains. A vault often refers to a secure burial chamber or above-ground structure designed to protect caskets. A columbarium, although it also pertains to the storage of cremated remains, is usually a wall or structure containing niches specifically for urns, rather than a communal receptacle for skeletal remains.