fibrillation

/ˌfɪbɹɪˈleɪʃən/

//ˌfɪbɹɪˈleɪʃən// noun

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

"fibrillation" is a 12-letter English headword indexed on PlainSpell.

The verdict

“fibrillation” has 17 generated spelling variants in the English index at frequency #36,142. The variants make it a useful spelling check.

#36,142
frequency rank, English
2,507
“F” headwords
17
tracked misspellings

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - The rapid, irregular, and unsynchronized contraction of the muscle fibers of the heart.

Corpus desk

Index EN-fibrillation · fibrillation · English

fibrillation · rank #36,142 · 17 variants · 0 confusables

  • FREQ-MID #36,142
  • LEN-MEGA 12 letters
  • VOW-5 5 vowels
  • CONFUS-0 No pairs
  • VAR-HIGH 17 variants
  • BOOK-MID 2,507
  • PHOTO-FINISH fissure

Nearest frequency peer: fissure (+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 “fibrillation”

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

corpus weight

What this shows “fibrillation” 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
Key facts for fibrillation
PropertyValue
Headwordfibrillation
LanguageEnglish
Part of speechNoun
IPA/ˌfɪbɹɪˈleɪʃən/
Letters12
Frequency rank#36,142
Misspellings tracked17
Confusable pairs0
SourceWiktionary (kaikki.org)

Frequency seat of misspelling magnet “fibrillation”

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).fibrillationlands 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 “fissure” (#36,143), “feverish” (#36,140), “fizzy” (#36,144). Among 2,507 “F” headwords, “fibrillation” is #36,142. Source: FrequencyWords open word-frequency list.

A misspelling magnet

The generator records 17 spelling variants around fibrillation (IPA /ˌfɪbɹɪˈleɪʃən/), anoun. Corpus frequency is #36,142 among 2,507 “F” headwords. Dominant gloss: "The rapid, irregular, and unsynchronized contraction of the muscle fibers of the heart.".

Our generated misspelling index lists 17 likely wrong-spelling variants for fibrillation, with forms such as "fbirillation", "ffibrillation", and "fibbrillation". 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. This headword has no recorded confusable partner, which typically means the spelling is too distinctive to be mistaken for another word.

Etymologically, the entry records: From fibrilla + -ation. The correct English form is fibrillation, spelled F-I-B-R-I-L-L-A-T-I-O-N.

Definition

  1. 1
    The rapid, irregular, and unsynchronized contraction of the muscle fibers of the heart.

Recorded use

Wiktionary examples

These source excerpts show how fibrillation appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. Though occasionally a “flatliner” can be revived with a defib, it is most commonly used to change the uncoordinated contractions of the heart (fibrillation) into a normal sinus rhythm—that is, to defibrillate the heart.
  2. The most common type of irregular heartbeat is atrial fibrillation or AFib. It is estimated that between three and six million people in the United States have AFib.

Etymology

From fibrilla + -ation.

This word in other languages

fibrilación(Español)fibrillation(Français)

Common misspellings

Also misspelled as:

  • fbirillation
  • ffibrillation
  • fibbrillation
  • fibirllation
  • fibrilaltion
  • fibrilation
  • fibrillaiton
  • fibrillasion
  • fibrillatino
  • fibrillationn
  • fibrillatoin
  • fibrillattion
  • fibrilltaion
  • fibrlilation
  • fibrrillation
  • firbillation
  • ifbrillation

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of fibrillation - measured in single-character edits (insert, delete, or substitute a letter). Larger bars are easier to catch; one-edit slips are the sneakiest.

fbirillation2ffibrillation1fibbrillation1fibirllation2fibrilaltion2fibrilation1fibrillaiton2fibrillasion1
Edit distance from "fibrillation"

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 "fibrillation"?
"fibrillation" is spelled F-I-B-R-I-L-L-A-T-I-O-N. The IPA pronunciation is /ˌfɪbɹɪˈleɪʃən/.
What does "fibrillation" mean?
As a noun, "fibrillation" means: The rapid, irregular, and unsynchronized contraction of the muscle fibers of the heart.
What are common misspellings of "fibrillation"?
Common misspellings include "fbirillation", "ffibrillation", "fibbrillation", "fibirllation", "fibrilaltion". The correct spelling is "fibrillation".
How do you pronounce "fibrillation"?
The IPA (International Phonetic Alphabet) transcription for "fibrillation" is /ˌfɪbɹɪˈleɪʃən/. 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 "fibrillation"?
From fibrilla + -ation. 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 "fibrillation", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 12 letters (nearest by frequency rank).

multimillion#36,256unremarkable#36,003undetectable#36,000technicality#35,979

Similar misspelling depth

Headwords with a similar count of attested misspellings (17 here; floor ≥5).

placeholder17 variantsunderweight17 variantspresumptive17 variantsproactively17 variants

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

Source: FrequencyWords open word-frequency list