Which to use
“onus” and “opus” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.
- #29,402
- “onus” frequency rank
- #23,619
- “opus” frequency rank
- 53021
- confusion score
Side-by-Side Comparison
| Feature | onus | opus |
|---|---|---|
| Definition | A legal obligation. | A work of music or set of works with a specified rank in an ordering of a composer's complete published works. |
Where the eye mixes onus and opus
Muted = shared; highlighted = the visual trap. They share 3 letters in sequence.
Visual trap between onus and opus
A purely visual mix-up. onus (/ˈəʊnəs/) and opus (/ˈəʊpəs/) 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 a single letter - n in “onus” becomes p in “opus”. Our composite confusion score for this pair is 53021, derived from the frequency rank of both members and their visual similarity.
onus is recorded at frequency rank #29,402, classified as anoun, pronounced /ˈəʊnəs/. opus is at rank #23,619, tagged as anoun, pronounced /ˈəʊpəs/.
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 53021, this pair ranks #152,316 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of onus vs opus
Shared letters: osu. Private to "onus": n. Private to "opus": p.
"onus" · 4 letters · shape VCVC · "opus" · 4 letters · shape VCVC
Known mistypes of this pair
Frequently Asked Questions
Is swapping "onus" for "opus" ever safe?
In ordinary English text, does "onus" or "opus" 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 "onus" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "opus" - compare definitions side by side with the headword page. Word entry
- This pair ranks #152,316 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "onus" and "opus" also get mixed up with nearby pairs, the highest-scored neighbour is "onus vs OWS". 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 #152,316 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.