What is the term for a container designed for placement in the grave around the casket?

The term "outer burial container" refers to a type of container that is placed in the grave around the casket. These containers serve several purposes, including protecting the casket from the weight of the earth above, preventing grave collapse, and providing a more stable environment for the casket. Outer burial containers can include burial vaults and grave liners, which are specifically designed to contain the casket and maintain the integrity of the burial site. Their use can also help to deter the elements from affecting the casket, ensuring that it remains intact during the decomposition process.

The other terms listed do not appropriately describe a container used in this context. A grave marker typically refers to a stone or plaque that indicates the location of a grave without being a physical container for a casket. A casket is the box in which the body is placed for viewing and burial, but it is not an outer container. A mausoleum is an above-ground structure designed to house the remains of the deceased, but it is not used to describe a container that goes into the ground.