Which to use
“sinus” and “sis” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.
- #20,225
- “sinus” frequency rank
- #12,501
- “sis” frequency rank
- 32726
- confusion score
Side-by-Side Comparison
| Feature | sinus | sis |
|---|---|---|
| Definition | A pouch or cavity in a bone or other tissue, especially one in the bones of the face or skull connecting with the nasal cavities (the paranasal sinus). | Clipping of sister. |
Where the eye mixes sinus and sis
Muted = shared; highlighted = the visual trap. They share 3 letters in sequence.
Look-alike desk: sinus vs sis
A purely visual mix-up. sinus (/ˈsaɪ.nəs/) and sis (/sɪs/) 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 2 letter(s) in length. Our composite confusion score for this pair is 32726, derived from the frequency rank of both members and their visual similarity.
sinus is recorded at frequency rank #20,225, classified as anoun, pronounced /ˈsaɪ.nəs/. sis is at rank #12,501, tagged as anoun, pronounced /sɪs/.
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 32726, this pair ranks #335,420 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of sinus vs sis
Shared letters: is. Private to "sinus": nu. Private to "sis": -.
"sinus" · 5 letters · shape CVCVC · "sis" · 3 letters · shape CVC
Known mistypes of this pair
- sinus ← isnus · sinnus · sinsu · sinuss · siuns · snius · ssinus
Frequently Asked Questions
Do "sinus" and "sis" mean the same thing in a sentence?
Which is more common, "sinus" or "sis"?
After this comparison
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "sinus" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "sis" - compare definitions side by side with the headword page. Word entry
- This pair ranks #335,420 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "sinus" and "sis" also get mixed up with nearby pairs, the highest-scored neighbour is "SIDS vs sinus". 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 #335,420 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.