FromFrench,kilo- irregularly derived fromAncient Greekχίλιοι(khílioi,“one thousand”). The etymologically "correct" form would bechili- orchilo-, resulting in forms such aschiliasme(“chiliasm”) orchilopode(“centipede”); but the French, when creating the prefix, had to avoid a possible (standard) pronunciation ofchi as/ʃi/, too close to the vulgar verbchier.
The letterk is not normally used in Catalan. Instead, Catalan orthography calls for using thequ digraph to represent the/k/ sound before ane or ani. Therefor, when the metric system was introduced into Catalan, the prefixkilo- was originally spelledquilo-. With the advent ofk as a standard international abbreviation, usage ofkilo- has become not only acceptable, but also more common than the traditional spelling. However, traditionalists still insist upon the use ofquilo-.
“kilo-”, in[EKSS] Eesti keele seletav sõnaraamat [Descriptive Dictionary of the Estonian Language] (in Estonian) (online version), Tallinn: Eesti Keele Sihtasutus (Estonian Language Foundation),2009
“kilo-”, inKielitoimiston sanakirja [Dictionary of Contemporary Finnish][3] (in Finnish) (online dictionary, continuously updated), Kotimaisten kielten keskuksen verkkojulkaisuja 35, Helsinki:Kotimaisten kielten tutkimuskeskus (Institute for the Languages of Finland),2004–, retrieved1 July 2023
“kilo-”, inSlovníkový portál Jazykovedného ústavu Ľ. Štúra SAV [Dictionary portal of the Ľ. Štúr Institute of Linguistics, Slovak Academy of Science] (in Slovak),https://slovnik.juls.savba.sk,2003–2026
