kilogram

Etymology

It is borrowed from French kilogramme,^[2][3][4][5] a French term of 1795,^[2][3][6] coined from kilo- (“thousand”) and gramme, the source of gram.^[2][7][5] Some early English forms were remodelled after Ancient Greek χίλιοι (khílioi, “thousand”).^[2]

Earliest recorded meaning

A metric unit of mass equal to one thousand grams: 1797, in the Journal of Natural Philosophy, spelled kilogramme at first.^[2][4][3]

Semantic evolution

The word belongs to the standard weights and measures devised in the 1790s by scientists working for the French National Convention, at a time when the regions of France had different standards.^[2][6] A unit based on the mass of a cubic decimetre of water was first defined in 1793 as the French grave (“heavy weight”), and kilogramme replaced that term by a law of 1795.^[2] The definition later moved from the water to a physical object: from 1831 the word is also recorded for a standard mass made to serve as a reference,^[2] and later dictionaries define the unit by a platinum-iridium cylinder kept near Paris.^[8][5][9] The shortening kilo is recorded from 1870.^[3][5]

Timeline

• 1795 – French kilogramme replaces the earlier term as the name of the unit in France.^[2]
• 1797 – the metric unit of one thousand grams, in English.^[2][4][5]
• 1831 – an object made to serve as a standard of mass, the prototype or standard kilogram.^[2]

Meanings

Noun

1. The base unit of mass in the metric system and the International System, equal to one thousand grams, or about 2.2 pounds: The parcel weighs two kilograms.^[2][9][8]
2. An object made to serve as a standard of this mass; a prototype kilogram.^[2][8]
3. A unit of force equal to the weight of a kilogram under standard gravity; a kilogram-force.^[5][8]

Word family

• kilogram-force
• kilogram calorie

Related words

• kilo
• kilo-
• gram
• -gram

Usage notes

The spelling kilogramme is especially British.^[10]

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
5. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ a b Cresswell, Julia (2021), Oxford Dictionary of Word Origins, 3rd ed., Oxford: Oxford University Press
7. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
8. ^ a b c d Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
9. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins
10. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House