fœtusvsfusTell them apart

Quick tell: fœtus is a noun, fus is a verb, so they fill different roles in a sentence.

Which to use

“fœtus” is a noun and “fus” is a verb - they look or sound alike but fill different roles in a sentence.

#19,296
“fœtus” frequency rank
#19,029
“fus” frequency rank
38325
confusion score

Side-by-Side Comparison

Feature fœtus fus
Definition Organisme en voie de développement, chez les animaux vivipares. Il a dépassé le stade d’embryon mais n’est pas encore né. Première personne du singulier du passé simple de être.

Where the eye mixes fœtus and fus

Muted = shared; highlighted = the visual trap. They share 3 letters in sequence. fœtus runs 5 letters (CVCVC) against fus's 3 (CVC) - the length gap alone is often enough to separate them once you know to check it.

5 ch
fœtus
3 ch
fus

Visual trap between fœtus and fus

These two trip readers on the page rather than in the ear: fœtus is \fe.tys\ while fus is \fy\. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 letter(s) in length, and the parts of speech differ too (noun vs verb), which is usually the fastest check. Our composite confusion score for this pair is 38325, derived from the frequency rank of both members and their visual similarity.

fœtus is recorded at frequency rank #19,296, classified as anoun, pronounced \fe.tys\. fus is at rank #19,029, tagged as averb, pronounced \fy\.

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 38325, this pair ranks #256,049 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of fœtus vs fus

Shared letters: fsu. Private to "fœtus": tœ. Private to "fus": -.

"fœtus" · 5 letters · shape CVCVC  ·  "fus" · 3 letters · shape CVC

Frequently Asked Questions

Do "fœtus" and "fus" mean the same thing in a sentence?
No - they are not even the same part of speech. "fœtus" is a noun and "fus" a verb, so a sentence built for one is usually ungrammatical with the other.
In ordinary French text, does "fœtus" or "fus" show up more?
"fus" is the more common of the two: it sits at frequency rank #19,029 in our French list, against #19,296 for "fœtus". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.

  • Full dictionary entry for "fœtus" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "fus" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #256,049 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "fœtus" and "fus" also get mixed up with nearby pairs, the highest-scored neighbour is "Fee vs fus". Nearby pair

Confusion rank #256,049 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