Measure of weight is a term used to describe the amount of mass an object has. A CARAT, which is five letters long, is a unit of weight for gemstones and is equal to 0.2 grams. A kilogram, which is eight letters long, is a metric unit of mass and is equal to 1, 000 grams. A GRAIN, which is five letters long, is a unit of mass equal to 0.065 grams. Kilo, which is four letters long, is a prefix meaning one thousand. A TON, which is three letters long, is a unit of mass equal to 2, 000 pounds. An OUNCE, which is five letters long, is a unit of mass equal to 28.35 grams. A POUND, which is five letters long, is a unit of mass equal to 453.59 grams. Lastly, a STONE, which is five letters long, is a unit of mass equal to 14 pounds.