Meanings
plural femtometres
- metrologyAn SI unit of length equal to 10⁻¹⁵ metres. Symbol: fm
Meronyms: yoctometre < zeptometre < attometre
2 more examples
Holonyms: picometre < nanometre < micrometre < millimetre < centimetre < decimetre < metre < kilometre < megametre < gigametre < terametre < petametre < exametre < zettametre < yottametre < ronnametre < quettametre
The speed of light is about 0.3 femtometres per yoctosecond.
Synonyms & antonyms
nouna metric unit of length equal to one quadrillionth of a meter
Synonym sets from Open English WordNet, CC BY 4.0.
Origin
- Proto-Indo-European*pénkʷe
- Proto-Germanic*fimf
- Proto-Indo-European*déḱm̥
- Proto-Germanic*tehun
- Proto-Germanic*fimftehun
- Old Norsefimmtán
- Danishfemten
- Englishfemto-
- Englishmetre
- Englishfemtometre
Translations
Bulgarian фемтоме́тър
- фемтоме́тър (femtométăr)10-15 of a metre
Chinese Mandarin 飛米 /飞米
- 飛米 /飞米 (fēimǐ)10-15 of a metre
Czech femtometr
- femtometr10-15 of a metre
French femtomètre
- femtomètre10-15 of a metre
German Femtometer
- Femtometer10-15 of a metre
Greek φεμτόμετρο
- φεμτόμετρο (femtómetro)10-15 of a metre
Italian femtometro
- femtometro10-15 of a metre
Japanese フェムトメートル
- フェムトメートル (femutomētoru)10-15 of a metre
Korean 펨토미터
- 펨토미터 (pemtomiteo)10-15 of a metre
Portuguese femtômetro
- femtômetro10-15 of a metre
Romanian femtometru
- femtometru10-15 of a metre
Spanish femtómetro
- femtómetro10-15 of a metre
Swedish femtometer
- femtometer10-15 of a metre
Turkish femtometre
- femtometre10-15 of a metre
Cite this entry
femtometre. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/femtometre
“femtometre.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/femtometre. Accessed November 4, 2026.
WatkinsX Dictionary, s.v. “femtometre,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/femtometre.
Source: femtometre on Wiktionary, CC BY-SA 4.0.