Gram, or Gramme, the standard unit of weight in the French or metric system. It is the weight of a cubic centimeter of pure, that is to say, distilled water, at zero centigrade. The multiples of the gram are formed by the use of the prefixes deca, hecto, kilo, and myria, meaning ten, one hundred, one thousand, and ten thousand grams respectively. The tenth and hundredth parts of a gram are denoted by prefixing deci and centi respectively. The gram is equivalent to 15.43248 grains Troy, or to .00220464 pounds avoirdupois. See METRIC SYSTEM.