1. (n.)International System of Units an internationally accepted system of physical units, using the meter, kilogram, second, ampere, kelvin, mole, and candela as the basic units of length, mass, time, electric current, temperature, amount of substance, and luminous intensity.
Etymology: (trans. of the earlier F name Système Internationale d'Unités)
Definition of 'international system of units'
Princeton's WordNet
1. (noun)Systeme International d'Unites, Systeme International, SI system, SI, SI unit, International System of Units, International System a complete metric system of units of measurement for scientists; fundamental quantities are length (meter) and mass (kilogram) and time (second) and electriccurrent (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"
Definition of 'international system of units'
U.S. National Library of Medicine
1. international system of units A system of physical units in which the fundamental quantities are length, time, mass, electric current, temperature, luminous intensity, and amount of substance, and the corresponding units are the meter, second, kilogram, ampere, kelvin, candela, and mole. The system has been givenofficial status and recommended for universal use by the GeneralConference on Weights and Measures.
Definitions of international system of units 
