Pennyweight: The pennyweight (abbreviated as dwt) is a unit of mass commonly used in the jewelry industry to measure the weight of precious metals, particularly gold and silver. One pennyweight is equal to 24 grains or approximately 1.555 grams.
A "slug," in the context of mass, is a unit of measurement primarily used in the United States customary and British imperial systems. It is not a widely used unit and is considered somewhat archaic. The slug is used to measure mass and is defined as the mass that accelerates at a rate of one foot per second squared (1 ft/s²) when a force of one pound-force (1 lbf) is applied to it. In other words, a slug is the mass that results in an acceleration of 1 ft/s² when a force of 1 lbf is applied to it.