Kilogram - Etymology and Usage

Etymology and Usage

The words "kilogramme" and "kilogram" are both derived from the French word "kilogramme", which itself was derived from the Greek words "χίλιοι" (chilioi), meaning "thousand" and "γράμμα" (gramma) meaning "a small weight". The word "kilogramme" was written into French law in 1795 and the French spelling was adopted in the United Kingdom when the word was used for the first time in English in 1797, with the spelling "kilogram" being adopted in the United States. In the United Kingdom both spellings are used, with "kilogram" having become by far the more common. UK law regulating the units to be used when trading by weight or measure does not prevent the use of either spelling.

In the 19th century the French word "kilo", a shortening of "kilogramme", was imported into the English language where it has been used to mean both kilogram and kilometre. While "kilo" is acceptable in many generalist texts, for example The Economist, its use is typically considered inappropriate in certain applications including scientific, technical and legal writing, where authors should adhere strictly to SI nomenclature." When the United States Congress gave the metric system a legal status in 1866, it permitted the use of the word "kilo" as an alternative to the word "kilogram", but in 1990 revoked the status of the word "kilo".

In 1948 the CGPM commissioned the CIPM to "to make recommendations for a single practical system of units of measurement, suitable for adoption by all countries adhering to the Metre Convention". This led to the launch of SI in 1960 and the subsequent publication of the "SI Brochure," which stated that "It is not permissible to use abbreviations for unit symbols or unit names ...".