Which to use
“FCO” is a name and “FIS” is a noun - they look or sound alike but fill different roles in a sentence.
- #49,916
- “FCO” frequency rank
- #40,245
- “FIS” frequency rank
- 90161
- confusion score
Side-by-Side Comparison
| Feature | FCO | FIS |
|---|---|---|
| Definition | Initialism of Foreign and Commonwealth Office. | Initialism of flight information service. |
Letter map: FCO vs FIS
Shared letters muted; letters that set FCO and FIS apart highlighted. Shared run: 1. FCO (CCV) and FIS (CVC) run the same length but a different consonant-vowel pattern - the shape difference is usually the fastest tell.
Part-of-speech tell for FCO / FIS
Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: FCO is aname and FISanoun. On the page they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 90161, derived from the frequency rank of both members and their visual similarity.
FCO is recorded at frequency rank #49,916, classified as aname. FIS is at rank #40,245, tagged as anoun.
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 90161, this pair ranks #4,440 of 530,003 scored English confusable pairs - among the most confusable pairs.
Orthographic DNA of FCO vs FIS
Shared letters: f. Private to "FCO": co. Private to "FIS": is.
"FCO" · 3 letters · shape CCV · "FIS" · 3 letters · shape CVC
Frequently Asked Questions
Do "FCO" and "FIS" mean the same thing in a sentence?
In ordinary English text, does "FCO" or "FIS" show up more?
Useful next steps
Done with this confusable. These links stay specific to "FCO" and "FIS".
- Full dictionary entry for "FCO" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "FIS" - compare definitions side by side with the headword page. Word entry
- This pair ranks #4,440 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "FCO" and "FIS" also get mixed up with nearby pairs, the highest-scored neighbour is "FCO vs FOMO". Nearby pair
Confusion rank #4,440 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.