pound

pound, abbr. lb, unit of either mass or force in the customary system of English units of measurement. Two different pounds of mass are defined, one in the avoirdupois system of units and one in the Troy system. The avoirdupois pound (lb avdp) is now defined in terms of the kilogram, the metric unit of mass; 1 lb avdp is equal to 0.45359237 kg. The Troy pound is used only for the measurement of precious metals and is defined as 5760/7000 of the avoirdupois pound. The apothecaries' pound is identical to the Troy pound. As a unit of force, or weight, the pound is the weight that a mass of 1 lb avdp has when the acceleration of gravity has its standard value (9.80665 meters per second per second). In ordinary usage, the term pound is often used without specifying whether force or mass is meant, but for scientific purposes it is important to make this distinction.

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pound

Unit of weight in the avoirdupois system, the traditional European system of weight (incorporated into the British Imperial system and the U.S. system of weights and measures), equal to 16 oz, 7,000 grains, or 0.4536 kg. It is also a unit of weight in the troy and apothecaries' systems (two other traditional systems of weight), equal to 12 troy or apothecaries' oz, 5,760 grains, or 0.37 kg. Its Roman ancestor, the libra, is the source of the abbreviation lb. The troy pound is used for precious metals, the apothecaries' pound for drugs. The British monetary pound is linked historically with the minting of silver coins (sterlings). Large payments were reckoned in “pounds of sterlings,” later shortened to “pounds sterling.” See also gram; International System of Units; measurement; metric system; ounce.

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pound - hash