SI unit

British

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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

SI unit Scientific

Any of the units of measure in the International System.
See more at International System

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The pressure of a gas may be expressed in the SI unit of pascal or kilopascal, as well as in many other units including torr, atmosphere, and bar.

From Textbooks • Feb. 14, 2019

In the International System, the SI unit of speed is the metre per second.

From New York Times • Sep. 22, 2016

The SI unit for time is the second, abbreviated s.

From Textbooks • Aug. 12, 2015

The SI unit for I is watts per meter squared.

From Textbooks • Aug. 12, 2015

The kelvin is the SI unit used in scientific work.

From Textbooks • Aug. 12, 2015

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023