obsvsopusTell them apart

Which to use

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

#34,614
“obs” frequency rank
#23,619
“opus” frequency rank
58233
confusion score

Side-by-Side Comparison

Feature obs opus
Definition Police observation. A work of music or set of works with a specified rank in an ordering of a composer's complete published works.

Letter map: obs vs opus

Shared letters muted; letters that set obs and opus apart highlighted. Shared run: 2.

3 ch
obs
4 ch
opus

Pair insight - obs / opus

obs and opus 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 58233, derived from the frequency rank of both members and their visual similarity.

obs is recorded at frequency rank #34,614, classified as anoun. 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 58233, this pair ranks #113,909 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of obs vs opus

Shared letters: os. Private to "obs": b. Private to "opus": pu.

"obs" · 3 letters · shape VCC  ·  "opus" · 4 letters · shape VCVC

Known mistypes of this pair

  • opusoppus · opsu · opuss · oups · pous

Frequently Asked Questions

Is swapping "obs" for "opus" ever safe?
No. They differ by 1 letter(s) in length, but the dictionary glosses above give them different meanings, so swapping one for the other changes what the sentence says.
Frequency check: "obs" vs "opus" - which ranks higher?
"opus" is the more common of the two: it sits at frequency rank #23,619 in our English list, against #34,614 for "obs". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Pair "obs" vs "opus" is on the table, pick a follow-up below.

  • Full dictionary entry for "obs" 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 #113,909 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "obs" and "opus" also get mixed up with nearby pairs, the highest-scored neighbour is "obs vs omi". 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 #113,909 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