Pound (mass) Pound (mass) The pound or pound-mass is a unit of mass used in the imperial, United States customary and other systems of measurement. Various definitions have been used; the most common today is the international avoirdupois pound, which is legally defined as exactly , and which is divided into 16 avoirdupois ounces. The international standard symbol for the avoirdupois pound is lb; an alternative symbol is lb (for most pound definitions), # (chiefly in the U.S.), and ℔ or ″̶ (specifically for the apothecaries' pound). The unit is descended from the Roman "libra" (hence the abbreviation "lb"). The English word
Anglo-Saxon pound Thomas Snelling writes that the division of the pound into 12 ounces was in use with the Romans, and the division of ounces into 20 pennyweights was introduced into France by Charlemagne, and then brought to England by William the Conqueror. The Latin word for "pound" is libra. The £ or ₤ is a stylised writing of the letter L, a short way of writing libra. This is similar to how a pound of mass is abbreviated "lb". Up until 1972, especially on typewriters or keyboards without a "£" symbol, it was common to write "L" or "l" instead of