An empty, enclosed compartment separating other compartments is called?

The term that refers to an empty, enclosed compartment separating other compartments is "voids." Voids are specifically designed as spaces that do not contain cargo or other materials; instead, they serve structural and safety purposes, often contributing to the integrity and stability of the overall structure. In marine and civil engineering contexts, voids can help manage weight distribution and enhance buoyancy.

Understanding other terms in the given context clarifies why they are not the correct choice. For example, a bulkhead refers to a wall within a ship or a building that provides structural support and separates different sections, and while it can be related to compartments in a ship, it does not denote an empty space. Compartments refer more broadly to spaces that might be filled or used for storage. Holds specifically denote the areas where cargo is stored on a ship, which do not align with the definition of an empty compartment needed for this question.