Which to use
“FOSS” is a noun and “four” is a num - they look or sound alike but fill different roles in a sentence.
- #33,655
- “FOSS” frequency rank
- #272
- “four” frequency rank
- 33927
- confusion score
Side-by-Side Comparison
| Feature | FOSS | four |
|---|---|---|
| Definition | Initialism of Free and Open Source Software. | A numerical value equal to 4; the number after three and before five; two plus two. This many dots (••••) |
Where the eye mixes FOSS and four
Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.
Look-alike desk: FOSS vs four
These two trip readers on the page rather than in the ear: FOSS is /fɒs/ while four is /foɹ/. Spoken aloud the problem disappears. In writing it persists, because they share most of their letters but differ in 2 positions, and the parts of speech differ too (noun vs num), which is usually the fastest check. Our composite confusion score for this pair is 33927, derived from the frequency rank of both members and their visual similarity.
FOSS is recorded at frequency rank #33,655, classified as anoun, pronounced /fɒs/. four is at rank #272, tagged as anum, pronounced /foɹ/.
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 33927, this pair ranks #325,201 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of FOSS vs four
Shared letters: fo. Private to "FOSS": s. Private to "four": ru.
"FOSS" · 4 letters · shape CVCC · "four" · 4 letters · shape CVVC
Known mistypes of this pair
Frequently Asked Questions
Do "FOSS" and "four" mean the same thing in a sentence?
In ordinary English text, does "FOSS" or "four" show up more?
What to do next
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "FOSS" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "four" - compare definitions side by side with the headword page. Word entry
- This pair ranks #325,201 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "FOSS" and "four" also get mixed up with nearby pairs, the highest-scored neighbour is "FOMO vs FOSS". 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 #325,201 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.