SinavssinusTell them apart

Quick tell: Sina is a name, sinus is a noun, so they fill different roles in a sentence.

Which to use

“Sina” is a name and “sinus” is a noun - they look or sound alike but fill different roles in a sentence.

#34,286
“Sina” frequency rank
#20,225
“sinus” frequency rank
54511
confusion score

Side-by-Side Comparison

Feature Sina sinus
Definition A unisex given name from Scottish Gaelic. 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).

Letter map: Sina vs sinus

Shared letters muted; letters that set Sina and sinus apart highlighted. Shared run: 3. Sina runs 4 letters (CVCV) against sinus's 5 (CVCVC) - the length gap alone is often enough to separate them once you know to check it.

4 ch
Sina
5 ch
sinus

Role in the sentence - Sina and sinus

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: Sina is aname and sinusanoun. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 54511, derived from the frequency rank of both members and their visual similarity.

Sina is recorded at frequency rank #34,286, classified as aname. sinus is at rank #20,225, tagged as anoun, pronounced /ˈsaɪ.nəs/.

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 54511, this pair ranks #140,534 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of Sina vs sinus

Shared letters: ins. Private to "Sina": a. Private to "sinus": u.

"Sina" · 4 letters · shape CVCV  ·  "sinus" · 5 letters · shape CVCVC

Known mistypes of this pair

  • Sina ← isna · sinna · snia · ssina
  • sinus ← isnus · sinnus · sinsu · sinuss · siuns · snius · ssinus

Frequently Asked Questions

Can "Sina" and "sinus" be used interchangeably?
No - they are not even the same part of speech. "Sina" is a name and "sinus" a noun, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "Sina" or "sinus"?
"sinus" is the more common of the two: it sits at frequency rank #20,225 in our English list, against #34,286 for "Sina". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

You've compared "Sina" and "sinus". Here's where to go from here.

  • Full dictionary entry for "Sina" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "sinus" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #140,534 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "Sina" and "sinus" also get mixed up with nearby pairs, the highest-scored neighbour is "Sina vs sura". 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 #140,534 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