A more thorough explanation:

Definition: When a ship is loaded with cargo that is not packaged and instead lies loose in the hold, it is said to be laden in bulk. This is a term used in maritime law.

Examples:

• A ship carrying a load of corn that is not packaged is said to be laden in bulk.
• Another example of a bulk cargo is salt.

The examples illustrate that cargoes of corn, salt, and similar items are usually shipped in bulk. This means that the cargo is not packaged and is instead loaded directly into the hold of the ship. This is different from packaged cargo, which is loaded into containers or other packaging before being loaded onto the ship.