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.
In the United States, a "hundredweight" (abbreviated as cwt) is a unit of weight or mass used in various industries, especially in agriculture and commerce. The hundredweight is equivalent to 100 pounds (lbs). It is often used to express weights or quantities of goods, particularly in contexts like the sale of agricultural products, grains, and some industrial materials.
1 hundredweight (US) = 100 pounds (lbs)
Hundredweights are commonly used in trade and commerce, especially for bulk items where the use of pounds or tons may not be as convenient. It provides a middle-ground unit for measuring weight between the pound and the ton. When you see prices or quantities listed in hundredweights in the United States, it means that they are referring to units of 100 pounds each.