fermi

/ˈfɜː(ɹ)mi/

//ˈfɜː(ɹ)mi// noun

By · According to Wiktionary data (CC BY-SA) ·

"fermi" is a 5-letter English headword indexed on PlainSpell.

The verdict

“fermi” has 7 generated spelling variants in the English index at frequency #35,718. The variants make it a useful spelling check.

#35,718
frequency rank, English
2,507
“F” headwords
7
tracked misspellings
17
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - An obsolete name of the unit of length equal to one femtometre (10⁻¹⁵ m).

Corpus desk

Index EN-fermi · fermi · English

fermi · rank #35,718 · 7 variants · 17 confusables

  • FREQ-MID #35,718
  • LEN-MID 5 letters
  • VOW-2 2 vowels
  • CONFUS-HIGH 17 pairs
  • VAR-MID 7 variants
  • BOOK-MID 2,507
  • PHOTO-FINISH fen

Nearest frequency peer: fen (-1 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.

Rank peers near misspelling magnet “fermi”

Same rarity band: useful when a typo lands on a peer headword

corpus weight

What this shows “fermi” sits among these FrequencyWords peers; misspelling depth is tracked separately in the edit-distance chart.

Source FrequencyWords open word-frequency list As of September 3, 2026

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

fermi vs form
60% similar
fermi vs firm
60% similar
fermi vs fern
60% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for fermi
PropertyValue
Headwordfermi
LanguageEnglish
Part of speechNoun
IPA/ˈfɜː(ɹ)mi/
Letters5
Frequency rank#35,718
Misspellings tracked7
Confusable pairs17
SourceWiktionary (kaikki.org)

Frequency seat of misspelling magnet “fermi”

This scale runs from the tiny cluster of words that carry ordinary speech (left) to the long tail of words almost nobody reaches for (right).fermilands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

The axis is logarithmic, with each marked tick roughly ten times rarer than the last. Same rarity band neighbours include “fen” (#35,717), “fiddler” (#35,719), “fanart” (#35,716). Among 2,507 “F” headwords, “fermi” is #35,718. Source: FrequencyWords open word-frequency list.

A misspelling magnet

The generator records 7 spelling variants around fermi (IPA /ˈfɜː(ɹ)mi/), anoun. Corpus frequency is #35,718 among 2,507 “F” headwords. Dominant gloss: "An obsolete name of the unit of length equal to one femtometre (10⁻¹⁵ m).".

Our generated misspelling index lists 7 likely wrong-spelling variants for fermi, with forms such as "efrmi", "femri", and "ferim". Every one of these variants traces to a single-character edit -- an added or dropped letter, a swapped consonant, or a vowel swap -- the kind of slip a spell-checker is built to catch. It also participates in 17 confusable-pair relationships, "form", "firm", "fern", and more, since the words sound or look close enough that writers reach for the wrong one mid-sentence.

Etymologically, the entry records: Named after Italian physicist Enrico Fermi. The correct English form is fermi, spelled F-E-R-M-I.

Definition

  1. 1
    An obsolete name of the unit of length equal to one femtometre (10⁻¹⁵ m).

Etymology

Named after Italian physicist Enrico Fermi.

Common misspellings

Also misspelled as:

  • efrmi
  • femri
  • ferim
  • fermmi
  • ferrmi
  • ffermi
  • fremi

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of fermi - expressed in single-character edits (insert, delete, or swap one letter). Bigger bars stand out at a glance; a one-edit slip is the hardest to catch.

efrmi2femri2ferim2fermmi1ferrmi1ffermi1fremi2
Edit distance from "fermi"

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

How do you spell "fermi"?
"fermi" is spelled F-E-R-M-I. The IPA pronunciation is /ˈfɜː(ɹ)mi/.
What does "fermi" mean?
As a noun, "fermi" means: An obsolete name of the unit of length equal to one femtometre (10⁻¹⁵ m).
What words are commonly confused with "fermi"?
"fermi" is commonly confused with "form", "firm", "fern". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "fermi"?
The IPA (International Phonetic Alphabet) transcription for "fermi" is /ˈfɜː(ɹ)mi/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "fermi"?
Named after Italian physicist Enrico Fermi. See the full etymology section above for more details.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "fermi", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 5 letters (nearest by frequency rank).

gaudy#35,731gauss#35,732gazed#35,734dusky#35,700

Similar misspelling depth

Headwords with a similar count of attested misspellings (7 here; floor ≥5).

fallow7 variantsgobble7 variantsgrays7 variantsgrout7 variants

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

Source: FrequencyWords open word-frequency list