Which to use
“once” and “onyx” are a confusable French pair: similar on the page, but distinct in meaning, check the gloss before you choose.
- #11,815
- “once” frequency rank
- #42,501
- “onyx” frequency rank
- 54316
- confusion score
Side-by-Side Comparison
| Feature | once | onyx |
|---|---|---|
| Definition | Unité de mesure de la masse (système impérial britannique avoirdupois), qui vaut 28,3495231 grammes pour l'once commune → voir ounce. Ses symboles sont oz et ℥. L'once troy (troy ounce) équivaut pour sa part à 31,1034768 grammes. | Parfum antique. |
Where the eye mixes once and onyx
Muted = shared; highlighted = the visual trap. They share 2 letters in sequence. once (VCCV) and onyx (VCVC) run the same length but a different consonant-vowel pattern - the shape difference is usually the fastest tell.
Why the eye confuses once with onyx
A purely visual mix-up. once (\ɔ̃s\) and onyx (\ɔ.niks\) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 54316, derived from the frequency rank of both members and their visual similarity.
once is recorded at frequency rank #11,815, classified as anoun, pronounced \ɔ̃s\. onyx is at rank #42,501, tagged as anoun, pronounced \ɔ.niks\.
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 54316, this pair ranks #134,847 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of once vs onyx
Shared letters: no. Private to "once": ce. Private to "onyx": xy.
"once" · 4 letters · shape VCCV · "onyx" · 4 letters · shape VCVC
Known mistypes of this pair
Frequently Asked Questions
Can "once" and "onyx" be used interchangeably?
Which is more common, "once" or "onyx"?
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 "once" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "onyx" - compare definitions side by side with the headword page. Word entry
- This pair ranks #134,847 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "once" and "onyx" also get mixed up with nearby pairs, the highest-scored neighbour is "ones vs onyx". 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 #134,847 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.