What is an outer burial container for a casket that possesses sealing qualities called?

An outer burial container that possesses sealing qualities is referred to as a vault. This type of container is designed to encase a casket, providing protection against the elements, such as water and soil. The sealing qualities of a vault help to prevent water and soil from entering the container, thus maintaining the integrity of the casket and its contents over time.

Burial vaults serve both practical and symbolic purposes in the funeral industry. Practically, they protect the casket from damage during the burial process and over time by external environmental factors. Symbolically, they represent the final resting place of the deceased, serving as a mark of respect.

In contrast, an urn is typically used for holding cremated remains, while a burial case refers more generally to any container used for interring human remains. A casket specifically pertains to the container for the deceased that usually presents the body for visitation or burial but does not inherently offer the same sealing qualities or protections as a vault. Hence, the term "vault" accurately captures the essence of an outer burial container that offers sealing qualities.