MFB

noun

"mfb" is a 3-letter English headword indexed on PlainSpell.

The verdict

“MFB” is uncommon English (frequency #87,553 among 4,057 “M” headwords), classed as a noun. The kind of spelling people second-guess.

#87,553
frequency rank, English
4,057
“M” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Initialism of medial forebrain bundle.

Corpus desk

Index EN-mfb · MFB · English

MFB · rank #87,553 · 0 variants · 0 confusables

  • FREQ-RARE #87,553
  • LEN-MID 3 letters
  • VOW-0 0 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 4,057
  • PHOTO-FINISH Menken

Nearest frequency peer: Menken (-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 “MFB”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

What this shows Long-tail view: where “MFB” sits against similarly uncommon English ranks.

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for MFB
PropertyValue
HeadwordMFB
LanguageEnglish
Part of speechNoun
Letters3
Frequency rank#87,553
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Where “MFB” sits in English frequency

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).MFBlands here:

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

Ticks step logarithmically, so each one marks a roughly tenfold drop in how often the word turns up. Same rarity band neighbours include “Menken” (#87,551), “melodically” (#87,550), “micromanagement” (#87,557). Source: FrequencyWords open word-frequency list.

Rare enough to double-check

MFB is uncommon English at frequency #87,553 among 4,057 “M” headwords, classed as anoun. Rarity is why readers land here mid-draft. Gloss: "Initialism of medial forebrain bundle.".

No misspelling variants are generated for MFB in our index, typically a sign the spelling maps closely to how the word sounds. Our confusable-pair dataset has no match for it, since nothing in our dataset looks or sounds close enough to cause mix-ups.

This entry carries no recorded etymology, leaving phoneme-to-grapheme mapping as the best guide to its spelling rather than a borrowing history. The correct English form is MFB, spelled M-F-B.

Definition

  1. 1
    Initialism of medial forebrain bundle.

Recorded use

Wiktionary example

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

  1. Using Diffusion Tensor Imaging Fiber Tracking (DTI FT) the authors describe potential converging ascending and descending MFB and anterior thalamic radiation (ATR) that may mediate major brain reward-seeking and punishment functions. Authors highlight novel connectivity, such as supero-lateral-branch MFB and ATR convergence, caudally as well as rostrally,…

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 "MFB"?
"MFB" is spelled M-F-B.
What does "MFB" mean?
As a noun, "MFB" means: Initialism of medial forebrain bundle.
What language does "MFB" come from?
"MFB" is a English word. You can look up definitions, pronunciations, and spelling data for this and other words across English, Spanish, Portuguese, French, and German on PlainSpell.
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 "MFB", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 3 letters (nearest by frequency rank).

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

Source: FrequencyWords open word-frequency list