International System of Units

noun phrase

: a system of units based on the metric system and developed and refined by international convention especially for scientific work

—abbreviation SI

Examples of International System of Units in a Sentence

Recent Examples on the Web

Under the International System of Units, which is based on the metric system that the rest of the world uses, a pascal (Pa) is the standard unit of pressure; a pascal is the pressure that the force of one newton puts perpendicularly onto an area of one square meter. —Matt Crisara, Popular Mechanics, 14 June 2023

In addition to keeping the national time, NIST helps maintain the International System of Units—meters, kilograms, and the like. —Tom Vanderbilt, Harper's Magazine, 13 Mar. 2023

Word History

First Known Use

1932, in the meaning defined above

Kids Definition

International System of Units

noun

: a system of units based on the metric system and used by international agreement especially for scientific work

Medical Definition

International System of Units

noun

In·​ter·​na·​tion·​al System of Units ˌint-ər-ˈnash-nəl-, -ənᵊl- 

: an internationally accepted system of units based on the metric system and having the meter, kilogram, second, ampere, kelvin, mole, and candela as base units, the radian and steradian as supplementary units, and deriving all other units from these

—abbreviation SI

called also International System