IFR
"ifr" is a 3-letter English headword indexed on PlainSpell.
The verdict
“IFR” is uncommon English (frequency #53,011 among 2,140 “I” headwords), classed as a noun. The kind of spelling people second-guess.
- #53,011
- frequency rank, English
- 2,140
- “I” headwords
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Initialism of instrument flight rules, a set of rules for a pilot flying on instruments, primarily as a means of navigating through inclement weather.
Corpus desk
Index EN-ifr · IFR · English
IFR · rank #53,011 · 0 variants · 0 confusables
- FREQ-RARE #53,011
- LEN-MID 3 letters
- VOW-1 1 vowel
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-MID 2,140
- PHOTO-FINISH hypothesize
Nearest frequency peer: hypothesize (-2 rank slots)
Read with this headword: Spelling guide for this pattern
Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.
Long-tail ranks near “IFR”
Sparse band: bars invert rank so rarer forms read shorter
- hulking
hulking
46,996 corpus weight
- hypnotist
hypnotist
46,993 corpus weight
- hypothesize
hypothesize
46,992 corpus weight
- IFR
IFR
46,990 corpus weight
- Iloilo
Iloilo
46,988 corpus weight
- infamously
infamously
46,985 corpus weight
What this shows Long-tail view: where “IFR” sits against similarly uncommon English ranks.
| Property | Value |
|---|---|
| Headword | IFR |
| Language | English |
| Part of speech | Noun |
| Letters | 3 |
| Frequency rank | #53,011 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Long-tail rank of “IFR” in English
Rare enough to double-check
IFR is uncommon English at frequency #53,011 among 2,140 “I” headwords, classed as anoun. Rarity is why readers land here mid-draft. 2 senses are on record.
Our edit-distance generator produced no likely misspellings for IFR, since its letter sequence doesn't invite the usual edit-distance slips. No close-neighbour confusable shows up for this headword in our dataset, since no other headword is close enough in sound or shape to pair with it.
No documented word history exists for this headword, so its spelling is easiest explained by how it's pronounced rather than where it came from. The correct English form is IFR, spelled I-F-R.
Definition
- 1Initialism of instrument flight rules, a set of rules for a pilot flying on instruments, primarily as a means of navigating through inclement weather.
- 2Initialism of infection fatality rate.
Recorded use
Wiktionary exampleThese source excerpts show how IFR appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.
For quotations using this term, see Citations:IFR.
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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Similar English words by spelling shape
Same letter count and similar misspelling depth for "IFR", not the corpus desk frequency band.
Same letter count
Frequency-ranked English headwords with 3 letters (nearest by frequency rank).