onivsonusTell them apart

Which to use

“oni” and “onus” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#36,267
“oni” frequency rank
#29,402
“onus” frequency rank
65669
confusion score

Side-by-Side Comparison

Feature oni onus
Definition A Japanese evil spirit or demon. A legal obligation.

Where the eye mixes oni and onus

Muted = shared; highlighted = the visual trap. They share 2 letters in sequence. oni runs 3 letters (VCV) against onus's 4 (VCVC) - the length gap alone is often enough to separate them once you know to check it.

3 ch
oni
4 ch
onus

Why the eye confuses oni with onus

A purely visual mix-up. oni (/ˈəʊni/) and onus (/ˈəʊnəs/) 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 65669, derived from the frequency rank of both members and their visual similarity.

oni is recorded at frequency rank #36,267, classified as anoun, pronounced /ˈəʊni/. onus is at rank #29,402, tagged as anoun, pronounced /ˈəʊnəs/.

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 65669, this pair ranks #71,623 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of oni vs onus

Shared letters: no. Private to "oni": i. Private to "onus": su.

"oni" · 3 letters · shape VCV  ·  "onus" · 4 letters · shape VCVC

Known mistypes of this pair

  • onus ← onnus · onsu · onuss · ouns

Frequently Asked Questions

Do "oni" and "onus" mean the same thing in a sentence?
No. They are said differently (/ˈəʊni/ versus /ˈəʊnəs/) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
In ordinary English text, does "oni" or "onus" show up more?
"onus" is the more common of the two: it sits at frequency rank #29,402 in our English list, against #36,267 for "oni". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.

  • Full dictionary entry for "oni" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "onus" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #71,623 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "oni" and "onus" also get mixed up with nearby pairs, the highest-scored neighbour is "omi vs oni". 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 #71,623 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list