costvscsiConfusable pair

Which to use

“cost” and “csi” are a confusable French pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#14,234
“cost” frequency rank
#30,552
“csi” frequency rank
44786
confusion score

Side-by-Side Comparison

Feature cost csi
Definition Coût. Ksi.

Where the eye mixes cost and csi

Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.

4 ch
cost
3 ch
csi

Look-alike desk: cost vs csi

A purely visual mix-up. cost (\kɒst\) and csi (\ˈksi\) 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 1 letter(s) in length. Our composite confusion score for this pair is 44786, derived from the frequency rank of both members and their visual similarity.

cost is recorded at frequency rank #14,234, classified as anoun, pronounced \kɒst\. csi is at rank #30,552, tagged as anoun, pronounced \ˈksi\.

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 44786, this pair ranks #207,827 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of cost vs csi

Shared letters: cs. Private to "cost": ot. Private to "csi": i.

"cost" · 4 letters · shape CVCC  ·  "csi" · 3 letters · shape CCV

Known mistypes of this pair

  • costccost · cosst · costt · cots · csot · ocst

Frequently Asked Questions

Is swapping "cost" for "csi" ever safe?
No. They are said differently (\kɒst\ versus \ˈksi\) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Which is more common, "cost" or "csi"?
"cost" is the more common of the two: it sits at frequency rank #14,234 in our French list, against #30,552 for "csi". 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 "cost" and "csi" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "cost" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "csi" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #207,827 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "cost" and "csi" also get mixed up with nearby pairs, the highest-scored neighbour is "CCE vs csi". 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 #207,827 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list