noun

1. The system of measurements developed in France in the 1790s and now used worldwide.

2. The modern version of that system, Systeme Internationale d'Unites (International System of Units), or SI system of measurements that is based on the base units of the meter/metre, the kilogram, the second, the ampere, the kelvin, the mole, and the candela.

3. Any variant of that system, that was not codified as SI, such as cgs.

Synonyms: SI, metric