A complete metric system of units of measurement for scientists; fundamental quantities are length (meter) and mass (kilogram) and time (second) and electric current (ampere) and temperature (kelvin) and amount of matter (mole) and luminous intensity (candela):
— Today the United States is the only country in the world not totally committed to the Systeme International d'Unites.

synonyms: International System, International System of Units, SI, SI system, SI unit, Systeme International.

Dutch: Système International
Polish: Międzynarodowy Układ Jednostek Miar, układ SI