"one thousand grams," standard of mass in the metric system, 1797, from French kilogramme (1795); see kilo- + gram.
Entries linking to kilogram
kilo-
word-forming element meaning "one thousand," introduced in French 1795, when the metric system was officially adopted there; irregularly reduced from Greek khilioi "thousand," from PIE *gheslo- "thousand," source also of Sanskrit sahasra-, Avestan hazanjra "thousand." "It is usually assumed that Lat. mille should be connected too" [Beekes]; see milli-. "In the metric system, kilo- means multiplied, & milli- divided, by 1000" [Fowler].
gram n.
also gramme, metric unit of weight, 1797, from French gramme (18c.), from Late Latin gramma "small weight," from Greek gramma "small weight," a special use of the classical word meaning "a letter of the alphabet" (see -gram). Adopted into English about two years before it was established in France as a unit in the metric system by law of 19 frimaire, year VIII (1799). "There seems to be no possible objection to adopting the more convenient shorter form, except that the -me records the unimportant fact that the word came to us through French" [Fowler].
kilo n.
1870, shortening of kilogram. Slang shortening key (in drug trafficking) is attested from 1968.