Which to use
“fifths” and “firth” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.
- #27,150
- “fifths” frequency rank
- #22,972
- “firth” frequency rank
- 50122
- confusion score
Side-by-Side Comparison
| Feature | fifths | firth |
|---|---|---|
| Definition | plural of fifth | An arm or inlet of the sea; a river estuary. |
Where the eye mixes fifths and firth
Muted = shared; highlighted = the visual trap. They share 4 letters in sequence.
Visual trap between fifths and firth
A purely visual mix-up. fifths (/fɪfθs/) and firth (/fɜːθ/) 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 50122, derived from the frequency rank of both members and their visual similarity.
fifths is recorded at frequency rank #27,150, classified as anoun, pronounced /fɪfθs/. firth is at rank #22,972, tagged as anoun, pronounced /fɜːθ/.
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 50122, this pair ranks #177,153 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of fifths vs firth
Shared letters: fhit. Private to "fifths": s. Private to "firth": r.
"fifths" · 6 letters · shape CVCCCC · "firth" · 5 letters · shape CVCCC
Known mistypes of this pair
Frequently Asked Questions
Can "fifths" and "firth" be used interchangeably?
In ordinary English text, does "fifths" or "firth" show up more?
Useful next steps
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "fifths" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "firth" - compare definitions side by side with the headword page. Word entry
- This pair ranks #177,153 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "fifths" and "firth" also get mixed up with nearby pairs, the highest-scored neighbour is "firth vs frith". 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 #177,153 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.