CairovsCSIROWhich spelling fits?

Which to use

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

#9,021
“Cairo” frequency rank
#42,077
“CSIRO” frequency rank
51098
confusion score

Side-by-Side Comparison

Feature Cairo CSIRO
Definition The capital city of Egypt. Initialism of Commonwealth Scientific and Industrial Research Organisation, a research institute in Australia.

Letter map: Cairo vs CSIRO

Shared letters muted; letters that set Cairo and CSIRO apart highlighted. Shared run: 4.

5 ch
Cairo
5 ch
CSIRO

Pair insight - Cairo / CSIRO

Cairo and CSIRO 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 a single letter - a in “Cairo” becomes s in “CSIRO”. Our composite confusion score for this pair is 51098, derived from the frequency rank of both members and their visual similarity.

Cairo is recorded at frequency rank #9,021, classified as aname, pronounced /ˈkaɪ.ɹoʊ/. CSIRO is at rank #42,077, tagged as aname.

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 51098, this pair ranks #168,404 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of Cairo vs CSIRO

Shared letters: cior. Private to "Cairo": a. Private to "CSIRO": s.

"Cairo" · 5 letters · shape CVVCV  ·  "CSIRO" · 5 letters · shape CCVCV

Known mistypes of this pair

  • Cairoaciro · caior · cairro · cario · ccairo · ciaro
  • CSIROccsiro · cisro · csior · csirro · csrio · cssiro · sciro

Frequently Asked Questions

Is swapping "Cairo" for "CSIRO" ever safe?
No. They differ by a single letter - a in “Cairo” becomes s in “CSIRO”, but the dictionary glosses above give them different meanings, so swapping one for the other changes what the sentence says.
Frequency check: "Cairo" vs "CSIRO" - which ranks higher?
"Cairo" is the more common of the two: it sits at frequency rank #9,021 in our English list, against #42,077 for "CSIRO". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

You've compared "Cairo" and "CSIRO". Here's where to go from here.

  • Full dictionary entry for "Cairo" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "CSIRO" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #168,404 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "Cairo" and "CSIRO" also get mixed up with nearby pairs, the highest-scored neighbour is "cair vs CSIRO". 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 #168,404 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