SI unit noun
- See under International System of Units.
British Dictionary definitions for si unit SI unit noun
- any of the units adopted for international use under the Système International d’Unités, now employed for all scientific and most technical purposes. There are seven fundamental units: the metre, kilogram, second, ampere, kelvin, candela, and mole; and two supplementary units: the radian and the steradian. All other units are derived by multiplication or division of these units without the use of numerical factors
si unit in Science SI unit
- Any of the units of measure in the International System. See more at International System.