FBI
/ˈɛf.biː.aɪ/
"fbi" is a 3-letter English headword indexed on PlainSpell.
The verdict
“FBI” is a regularly-used English word, ranked #3,429 in English word frequency and used as a proper noun.
- #3,429
- frequency rank, English
- 3
- letters
- 20
- confusable pairs
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Initialism of Federal Bureau of Investigation.
Visual similarity to commonly confused words
How many letter changes separate each confused pair (Levenshtein distance, normalized).
Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).
| Property | Value |
|---|---|
| Headword | FBI |
| Language | English |
| Part of speech | Proper noun |
| IPA | /ˈɛf.biː.aɪ/ |
| Letters | 3 |
| Frequency rank | #3,429 |
| Misspellings tracked | 0 |
| Confusable pairs | 20 |
| Source | Wiktionary (kaikki.org) |
Where “FBI” sits in English frequency
Spelling & Dictionary Insight
The English entry for FBI is 3 letters long, classified as a proper noun, and transcribed in the International Phonetic Alphabet as /ˈɛf.biː.aɪ/. Corpus data places it at rank #3,429 in overall English word frequency, indicating it appears regularly in written and spoken text. Wiktionary records 3 distinct senses for this headword, so context determines which meaning a reader should apply.
FBI doesn't appear in our generated misspelling index, and the word's spelling is regular enough that our generator found nothing worth flagging. It also participates in 20 confusable-pair relationships, "fi", "FL", "FM", and more, since the words sound or look close enough that writers reach for the wrong one mid-sentence.
This entry carries no recorded etymology, so spelling patterns must be inferred from the word's phoneme-to-grapheme mapping rather than from a documented borrowing chain. The correct English form is FBI, spelled F-B-I.
Definition
- 1Initialism of Federal Bureau of Investigation.
- 2Federation of British Industry (1916–1965), forerunner of CBI (Confederation of British Industry).
- 3fire behaviour index
This word in other languages
Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.
Frequently Asked Questions
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Using “FBI”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is F-B-I - every other letter order is a misspelling in standard orthography.
- Say it as /ˈɛf.biː.aɪ/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
- Don't mix it up with “fi” - see the side-by-side comparison. FBI vs fi
- Browse more English words and confusable pairs in the same reference. English words
Data Source
Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.