FSI

noun

The verdict

“FSI” is uncommon French (frequency #75,712 among 3,276 “F” headwords), classed as a noun. The kind of spelling people second-guess.

#75,712
frequency rank, French
3,276
“F” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Forces de sécurité intérieures, ensemble des forces destinées à assurer la sécurité à l’intérieur d’un pays (entre autres la police).

Corpus desk

Index FR-fsi · FSI · French

FSI · rank #75,712 · 0 variants · 0 confusables

  • FREQ-RARE #75,712
  • LEN-MID 3 letters
  • VOW-1 1 vowel
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 3,276
  • PHOTO-FINISH fruste

Nearest frequency peer: fruste (-1 rank slots)

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.

Rangs de longue queue près de « FSI »

Bande clairsemée: les barres inversent le rang pour que le rare se lise plus court

corpus weight

What this shows Vue de longue queue: où « FSI » se situe face à des rangs français aussi rares.

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for FSI
PropertyValue
HeadwordFSI
LanguageFrench
Part of speechNoun
Letters3
Frequency rank#75,712
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Longue queue: rang de « FSI » en français

De gauche à droite: le peu qui porte la parole quotidienne, puis la longue queue quasi invisible.FSItombe dans cette queue de rareté:

#1#100#1K#10K#100K
← used constantlyrarely used →

L'échelle est logarithmique (chaque tic ≈ 10× plus rare). Voisins rares de la même bande: « fruste » (#75,711), « fue » (#75,713), « fuyants » (#75,714). Parmi 3,276 lemmes en « F », « FSI » est au #75,712. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

FSI is uncommon French at frequency #75,712 among 3,276 “F” headwords, classed as anoun. Rarity is why readers land here mid-draft. Gloss: "Forces de sécurité intérieures, ensemble des forces destinées à assurer la sécurité à l’intérieur d’un pays (entre autres la police).".

The misspelling generator found no plausible variants for FSI, suggesting the orthography follows predictable French patterns. Our dataset records no confusable match here, since its spelling is unusual enough that it doesn't cluster with a lookalike.

This entry's etymology isn't recorded, so its spelling is easiest to reason about phoneme by phoneme, absent a documented history. The correct French form is FSI, spelled F-S-I.

Definition

  1. 1
    Forces de sécurité intérieures, ensemble des forces destinées à assurer la sécurité à l’intérieur d’un pays (entre autres la police).

Recorded use

Wiktionary examples

These source excerpts show how FSI appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. Pour les forces de sécurité intérieure (FSI), il y a un sujet de lutte contre la criminalité et un sujet de souveraineté.
  2. S’agissant de la satisfaction vis-à-vis des forces de sécurité intérieures (FSI), il n’y a quasiment pas de différence entre les femmes et les hommes.

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 French corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "FSI"?
"FSI" is spelled F-S-I.
What does "FSI" mean?
As a noun, "FSI" means: Forces de sécurité intérieures, ensemble des forces destinées à assurer la sécurité à l’intérieur d’un pays (entre autres la police).
What language does "FSI" come from?
"FSI" is a French word. PlainSpell's reference spans five languages -- English, Spanish, Portuguese, French, and German -- with definitions, pronunciations, and spelling data for each.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Similar French words by spelling shape

Same letter count and similar misspelling depth for "FSI", not the corpus desk frequency band.

Same letter count

Frequency-ranked French headwords with 3 letters (nearest by frequency rank).

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list