or chiefly Brit  ki*lo*gramme  n 1  :  the base unit of mass in the International System of Units that is equal to the mass of a prototype agreed upon by international convention and that is nearly equal to the mass of 1000 cubic centimeters of water at the temperature of its maximum density  2  :  a unit of force equal to the weight of a kilogram mass under a gravitational attraction equal to that of the earth .
 
 
 
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