femto-

== English == === Etymology === From Danish femten (“fifteen”), with reference to the (negative) exponent in the relevant power of ten; the same principle also explains atto-. === Prefix === femto- In the International System of Units and other metric systems of units, multiplying the unit to which it is attached by 10−15 (short scale quadrillionth or long scale billiardth). Alternative form: f- (symbol) Antonym: peta- ==== Derived terms ==== ==== Translations ==== == Czech == === Pronunciation === IPA(key): [fɛmto ] === Prefix === femto- femto- (SI prefix for 10-15) ==== Derived terms ==== === Further reading === “femto-”, in Kartotéka Novočeského lexikálního archivu (in Czech) == Danish == === Etymology === Created in 1962, by the Danish physicist Henning Højgaard Jensen (1918–2001), from the number femten (“fifteen”). === Prefix === femto- femto- (SI prefix for 10-15) == Finnish == === Etymology === Internationalism (see English femto-). === Pronunciation === IPA(key): /ˈfemto-/, [ˈfe̞mt̪o̞-] === Prefix === femto- femto- ==== Derived terms ==== === Further reading === “femto-”, in Kielitoimiston sanakirja [Dictionary of Contemporary Finnish]‎[1] (in Finnish) (online dictionary, continuously updated), Kotimaisten kielten keskuksen verkkojulkaisuja 35, Helsinki: Kotimaisten kielten tutkimuskeskus (Institute for the Languages of Finland), 2004–, retrieved 2 July 2023 == French == === Pronunciation === IPA(key): /fɛm.to/ === Prefix === femto- femto- ==== Derived terms ==== == Indonesian == === Etymology === From English femto-, from Danish femten (“fifteen”), and the previous name of the femtometre, the fermi. === Pronunciation === IPA(key): [ˈfɛmto] Hyphenation: fém‧to === Prefix === fémto femto-: in the International System of Units and other metric systems of units, multiplying the unit to which it is attached by 10−15. Symbol: f ==== Derived terms ==== === Further reading === “femto-”, in Kamus Besar Bahasa Indonesia [Great Dictionary of the Indonesian Language] (in Indonesian), Jakarta: Agency for Language Development and Cultivation – Ministry of Education, Culture, Research, and Technology of the Republic of Indonesia, 2016 == Italian == === Prefix === femto- femto- ==== Derived terms ==== == Polish == === Etymology === Derived from Danish femten. === Pronunciation === IPA(key): /fɛm.tɔ/ Rhymes: -ɛmtɔ Syllabification: fem‧to- === Prefix === femto- femto- ‎femto- + ‎metr → ‎femtometr ==== Derived terms ==== === Further reading === “femto-”, in Polish dictionaries at PWN‎[2] (in Polish) == Spanish == === Etymology === From Danish and Norwegian femten (“fifteen”). === Pronunciation === IPA(key): /femto/ [fẽm.t̪o] Syllabification: fem‧to- === Prefix === femto- femto- (one quadrillionth, 10-15) ==== Derived terms ==== === Further reading === “femto-”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8.1, Royal Spanish Academy [Spanish: Real Academia Española], 15 December 2025 == Swedish == === Prefix === femto- femto-