Kilogram

Pronunciation

Alternative forms

• kilogramme

Origin

From French kilogramme, composed of kilo- + gramme.

Full definition of kilogram

Noun

1. In the International System of Units, the base unit of mass; conceived of as the mass of one liter of water, and now defined as the mass of a specific cylinder of platinum-iridium alloy kept at the International Bureau of Weights and Measures in France. Symbol: kg
2. (proscribed) Hence, the unit of weight such that a one-kilogram mass is also a one-kilogram weight.

Usage notes

(proscribed, unit of weight) The use of the kilogram as a unit of weight is somewhat imprecise, as weight can change while mass remains constant. The weight of a one-kilogram mass will depend on its location, because the pull of gravity varies from one place to another. It is therefore frequently proscribed, but is nonetheless in wide use (e.g., a person's weight in kilograms). (The same imprecision and proscription also occur with many other words pertaining to weight and mass, such as the verb weigh.)