Which to use
“sinister” is an adjective and “sister” is a noun - they look or sound alike but fill different roles in a sentence.
- #13,064
- “sinister” frequency rank
- #1,207
- “sister” frequency rank
- 14271
- confusion score
Side-by-Side Comparison
| Feature | sinister | sister |
|---|---|---|
| Definition | Inauspicious, ominous, unlucky, illegitimate (as in bar sinister). | A daughter of the same parents as another person; a female sibling. |
Where the eye mixes sinister and sister
Muted = shared; highlighted = the visual trap. They share 6 letters in sequence. sinister runs 8 letters (CVCVCCVC) against sister's 6 (CVCCVC) - the length gap alone is often enough to separate them once you know to check it.
Why the eye confuses sinister with sister
These two trip readers on the page rather than in the ear: sinister is /ˈsɪnɪstə/ while sister is /ˈsɪs.tə(ɹ)/. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 letter(s) in length, and the parts of speech differ too (adjective vs noun), which is usually the fastest check. Our composite confusion score for this pair is 14271, derived from the frequency rank of both members and their visual similarity.
sinister is recorded at frequency rank #13,064, classified as anadj, pronounced /ˈsɪnɪstə/. sister is at rank #1,207, tagged as anoun, pronounced /ˈsɪs.tə(ɹ)/.
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 14271, this pair ranks #471,030 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of sinister vs sister
Shared letters: eirst. Private to "sinister": n. Private to "sister": -.
"sinister" · 8 letters · shape CVCVCCVC · "sister" · 6 letters · shape CVCCVC
Known mistypes of this pair
Frequently Asked Questions
Do "sinister" and "sister" mean the same thing in a sentence?
Which is more common, "sinister" or "sister"?
Useful next steps
Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.
- Full dictionary entry for "sinister" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "sister" - compare definitions side by side with the headword page. Word entry
- This pair ranks #471,030 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "sinister" and "sister" also get mixed up with nearby pairs, the highest-scored neighbour is "sinister vs spinster". 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 #471,030 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.