femtoseconde
\fɛm.tɔ.sə.ɡɔ̃d\
The verdict
“femtoseconde” is uncommon French (outside the top frequency list), classed as a noun. The kind of spelling people second-guess.
- Unranked
- below top-frequency French
- 12
- letters
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Unité de mesure de temps du Système international (SI), valant 10⁻¹⁵ seconde, et dont le symbole est fs.
Corpus desk
Index FR-femtoseconde · femtoseconde · French
femtoseconde · unranked · 0 variants · 0 confusables
- FREQ-UNRANKED Unranked
- LEN-MEGA 12 letters
- VOW-5 5 vowels
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-THIN "F" thin
- PHOTO-UNK Peer pending
Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.
| Property | Value |
|---|---|
| Headword | femtoseconde |
| Language | French |
| Part of speech | Noun |
| IPA | \fɛm.tɔ.sə.ɡɔ̃d\ |
| Letters | 12 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Longue queue: rang de « femtoseconde » en français
Rare enough to double-check
femtoseconde is uncommon French outside the top frequency list, classed as anoun, transcribed \fɛm.tɔ.sə.ɡɔ̃d\. Rarity is why readers land here mid-draft. Gloss: "Unité de mesure de temps du Système international (SI), valant 10⁻¹⁵ seconde, et dont le symbole est fs.".
Our edit-distance generator produced no likely misspellings for femtoseconde, since its letter sequence doesn't invite the usual edit-distance slips. No confusable counterpart is on file for this word, which typically means the spelling is too distinctive to be mistaken for another word.
Wiktionary doesn't record an etymology for this headword, so its spelling is easiest explained by how it's pronounced rather than where it came from. The correct French form is femtoseconde, spelled F-E-M-T-O-S-E-C-O-N-D-E.
Definition
- 1Unité de mesure de temps du Système international (SI), valant 10⁻¹⁵ seconde, et dont le symbole est fs.
Recorded use
Wiktionary examplesThese source excerpts show how femtoseconde appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.
Les chiffres donnent le vertige: le système est capable d'atteindre un pic de 10 pétawatts (10 puissance 15 watts) pendant un temps ultra-bref, de l'ordre de la femtoseconde (un millionième de milliardième de seconde).
Le laser femtoseconde permet de fendre ou de cliver la cornée par une action photodisruptive.
This word in other languages
Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA). See the methodology for how each field is sourced and updated.