Dross refers to the waste or impurities that are removed from metals during the refining process. It is the residue that rises to the surface of the molten metal as it is purified. This substance can consist of various impurities that are not desired in the final product.

The concept of dross is not limited to metalworking; it is also used metaphorically to describe anything considered worthless, trivial, or of poor quality. In various contexts, especially in literature and spiritual discussions, "dross" can symbolize the removal of moral or spiritual impurities, aiming towards purification or improvement of one's character or society.

Therefore it is said, "Like Gold Refined Seven Times".