poissonvsprisonTell them apart

Which to use

“poisson” and “prison” are a confusable French pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#2,589
“poisson” frequency rank
#951
“prison” frequency rank
3540
confusion score

Side-by-Side Comparison

Feature poisson prison
Definition Animal possédant un squelette, généralement ovipare (mais parfois ovovivipare ou vivipare), vivant dans l’eau, et respirant généralement par des branchies (bien que certaines espèces aient des systèmes de respiration aérienne complémentaire, comme les poumons des dipneustes ou le labyrinthe des anabantidés). Endroit clos où sont enfermées les personnes condamnées à une peine de privation de liberté ou les prévenus en attente de jugement.

Where the eye mixes poisson and prison

Muted = shared; highlighted = the visual trap. They share 5 letters in sequence.

7 ch
poisson
6 ch
prison

Why the eye confuses poisson with prison

A purely visual mix-up. poisson (\pwa.sɔ̃\) and prison (\pʁi.zɔ̃\) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they differ by 1 letter(s) in length. Our composite confusion score for this pair is 3540, derived from the frequency rank of both members and their visual similarity.

poisson is recorded at frequency rank #2,589, classified as anoun, pronounced \pwa.sɔ̃\. prison is at rank #951, tagged as anoun, pronounced \pʁi.zɔ̃\.

Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.

With a confusion score of 3540, this pair ranks #433,785 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of poisson vs prison

Shared letters: inops. Private to "poisson": -. Private to "prison": r.

"poisson" · 7 letters · shape CVVCCVC  ·  "prison" · 6 letters · shape CCVCVC

Known mistypes of this pair

  • poissonopisson · piosson · poisosn · poissno · poissonn · posison · ppoisson
  • prisonpirson · pprison · priosn · prisno · prisonn · prisson · prrison · prsion

Frequently Asked Questions

Is swapping "poisson" for "prison" ever safe?
No. They are said differently (\pwa.sɔ̃\ versus \pʁi.zɔ̃\) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Which is more common, "poisson" or "prison"?
"prison" is the more common of the two: it sits at frequency rank #951 in our French list, against #2,589 for "poisson". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

Eye-level mix-up between "poisson" and "prison" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "poisson" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "prison" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #433,785 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "poisson" and "prison" also get mixed up with nearby pairs, the highest-scored neighbour is "pinson vs poisson". Nearby pair
  • Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes

Confusion rank #433,785 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list