The Avoirdupois Pound is a unit of weight commonly used in the United States and other countries that follow the imperial system. It is defined as exactly 0.45359237 kilograms. The term "avoirdupois" comes from Middle French, meaning "goods of weight," and it was historically used for trade and commerce. The Avoirdupois system includes other units like ounces and tons, with 16 ounces making up one pound. This system is distinct from the Troy Pound, which is used for precious metals. The Avoirdupois Pound is widely recognized and used in everyday measurements, such as food and body weight.