What is the term for a rigid container designed for encasing human remains?

The term for a rigid container designed for encasing human remains is "Casket." A casket is typically characterized by a rectangular shape and is often used in funerals to provide a dignified enclosure for the deceased. Caskets can be made from various materials, such as wood or metal, and they are often lined with fabric, offering a more refined and aesthetic presentation compared to other types of containers.

The other terms, while related to burial or interment, refer to different items. A coffin is generally tapered at the head and foot and can sometimes refer to the container for human remains, but in specific contexts, it may imply a different style or design. A vault refers to an outer burial container that holds the casket and provides additional protection from the elements as well as structural support. A coat, in this context, is unrelated, as it refers to an article of clothing rather than a burial container. Understanding these distinctions clarifies why "Casket" is the most appropriate term for the question asked.