International System of Units

American  

noun

1. an internationally accepted coherent system of physical units, derived from the MKSA (meter-kilogram-second-ampere) system, using the meter, kilogram, second, ampere, kelvin, mole, and candela as the basic units SI unitsSI unit respectively of the fundamental quantities of length, mass, time, electric current, temperature, amount of substance, and luminous intensity. SI

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Etymology

Origin of International System of Units

First recorded in 1930–35; translation of the earlier French name Système Internationale d'Unités

Example Sentences

The customary units we use legally are defined in terms of the International System of Units units.

From Washington Post • Nov. 30, 2018

As the National Nanotechnology Initiative explains, “In the International System of Units, the prefix ‘nano’ means one-billionth, or 10-9; therefore one nanometer is one-billionth of a meter.”

From Slate • Sep. 6, 2016

The kilogram is the last physical unit in the International System of Units defined by a physical artifact, a platinum-iridium cylinder kept by the International Bureau of Weights and Measures in Sèvres, France.

From Science Magazine • Jan. 11, 2013