Which to use
“FES” and “FOSS” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.
- #39,812
- “FES” frequency rank
- #33,655
- “FOSS” frequency rank
- 73467
- confusion score
Side-by-Side Comparison
| Feature | FES | FOSS |
|---|---|---|
| Definition | Initialism of floppy eyelid syndrome | Initialism of Free and Open Source Software. |
Letter map: FES vs FOSS
Shared letters muted; letters that set FES and FOSS apart highlighted. Shared run: 2. FES runs 3 letters (CVC) against FOSS's 4 (CVCC) - the length gap alone is often enough to separate them once you know to check it.
Pair insight - FES / FOSS
FES and FOSS are indexed as a confusable English pair. We have no recorded pronunciation or part of speech for both members, so the spelling overlap is what we can show you: they differ by 1 letter(s) in length. Our composite confusion score for this pair is 73467, derived from the frequency rank of both members and their visual similarity.
FES is recorded at frequency rank #39,812, classified as anoun. FOSS is at rank #33,655, tagged as anoun, pronounced /fɒs/.
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 73467, this pair ranks #39,516 of 530,003 scored English confusable pairs - among the most confusable pairs.
Orthographic DNA of FES vs FOSS
Shared letters: fs. Private to "FES": e. Private to "FOSS": o.
"FES" · 3 letters · shape CVC · "FOSS" · 4 letters · shape CVCC
Known mistypes of this pair
- FOSS ← ffoss · fos · fsos · ofss
Frequently Asked Questions
Do "FES" and "FOSS" mean the same thing in a sentence?
In ordinary English text, does "FES" or "FOSS" show up more?
Useful next steps
You've compared "FES" and "FOSS". Here's where to go from here.
- Full dictionary entry for "FES" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "FOSS" - compare definitions side by side with the headword page. Word entry
- This pair ranks #39,516 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "FES" and "FOSS" also get mixed up with nearby pairs, the highest-scored neighbour is "FES vs foh". 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 #39,516 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.