What is any container designed for placement in the grave around the casket or urn called?

The term "outer burial container" specifically refers to a protective container designed for placement in the grave surrounding a casket or urn. This type of container serves multiple important purposes, including providing structural support to the grave, preventing the collapse of the earth above and around the casket, and protecting the casket or urn from moisture and other environmental factors.

The outer burial container can be made from various materials, including concrete, metal, or plastic, and is often both a practical and a regulatory requirement in many cemeteries. By using an outer burial container, cemeteries can maintain their grounds more effectively and prevent issues related to subsidence and erosion over time.

In contrast, the other options do not accurately describe this function. A grave attachment might imply something added to a grave but does not specifically denote a container. A casket holder is not a commonly recognized term and does not represent an item that surrounds the casket in the grave context. A burial arrangement typically refers to the overall planning of the funeral and burial services rather than a specific container. Thus, the term "outer burial container" most accurately reflects the physical object in question.