What term describes an entity that must reference another entity for its data to be meaningful?

The correct term for an entity that must reference another entity for its data to be meaningful is a weak entity. A weak entity is dependent on a strong entity for its identification. It cannot exist on its own because it does not possess a complete set of attributes that uniquely identify it without the strong entity it is linked to.

In database design, a weak entity typically has a partial key, which is used along with the primary key of the strong entity to create a composite key. This relationship highlights the dependency of the weak entity, emphasizing that its existence and meaning are reliant on the presence of another entity in the database.

For instance, consider a database that contains information about orders and the items within those orders. An order item is a weak entity because it cannot be uniquely identified without referencing the order it belongs to. This is in contrast to strong entities, which can exist independently with their own complete identifiers.

In the context of the other choices, the concepts of strong, dependent, and linked entities do not capture the specific necessity of a weak entity’s reliance on another entity, thereby making weak entity the most precise term for this definition.