césiovscioWhich spelling fits?

Which to use

“césio” and “cio” are a confusable Portuguese pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#41,427
“césio” frequency rank
#22,564
“cio” frequency rank
63991
confusion score

Side-by-Side Comparison

Feature césio cio
Definition elemento químico de símbolo Cs, possui o número atômico 55 e massa atômica relativa 132,905 u; é um metal alcalino, de coloração ouro prateado; é encontrado em minerais de potássio, tais como micas, berílio, feldspatos e a polucita (alumínio-silicato de césio); o césio metálico é utilizado na fabricação de células fotoelétricas e detectores de infravermelho período de maior apetite sexual e fertilidade de certos animais

Where the eye mixes césio and cio

Muted = shared; highlighted = the visual trap. They share 3 letters in sequence. césio runs 5 letters (CVCVV) against cio's 3 (CVV) - the length gap alone is often enough to separate them once you know to check it.

5 ch
césio
3 ch
cio

Visual trap between césio and cio

A purely visual mix-up. césio (/ˈsɛzju/) and cio (/ˈsi.u/) 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 63991, derived from the frequency rank of both members and their visual similarity.

césio is recorded at frequency rank #41,427, classified as anoun, pronounced /ˈsɛzju/. cio is at rank #22,564, tagged as anoun, pronounced /ˈsi.u/.

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 63991, this pair ranks #5,961 of 75,631 scored Portuguese confusable pairs - among the most confusable pairs.

Orthographic DNA of césio vs cio

Shared letters: cio. Private to "césio": sé. Private to "cio": -.

"césio" · 5 letters · shape CVCVV  ·  "cio" · 3 letters · shape CVV

Frequently Asked Questions

Is swapping "césio" for "cio" ever safe?
No. They are said differently (/ˈsɛzju/ versus /ˈsi.u/) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Which is more common, "césio" or "cio"?
"cio" is the more common of the two: it sits at frequency rank #22,564 in our Portuguese list, against #41,427 for "césio". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Eye-level mix-up between "césio" and "cio" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "césio" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "cio" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #5,961 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
  • "césio" and "cio" also get mixed up with nearby pairs, the highest-scored neighbour is "césio vs cisto". Nearby pair

Confusion rank #5,961 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list