Although lumper is the most common name for this type of worker, they are also sometimes referred to as lumpers-on or lumpermen. The term lumper comes from the word lumps, meaning big pieces or chunks. This name is likely chosen because lumpers typically handles larger pieces of cargo than regular dock workers. In addition, lumpers are often hired on a per-job basis, as opposed to being part of a regular dock workers union. Because of this, they are sometimes known as lumpermen or lumpermen-on. Whatever you call them, these workers play an important role in loading and unloading cargo at warehouses, docks and ports.