filamentous

adj

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

"filamentous" is a 11-letter English headword indexed on PlainSpell.

The verdict

“filamentous” is uncommon English (frequency #66,663 among 2,507 “F” headwords), classed as an adjective. The kind of spelling people second-guess.

#66,663
frequency rank, English
2,507
“F” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Having the form of threads or filaments; filamented.

Corpus desk

Index EN-filamentous · filamentous · English

filamentous · rank #66,663 · 0 variants · 0 confusables

  • FREQ-RARE #66,663
  • LEN-MEGA 11 letters
  • VOW-5 5 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 2,507
  • PHOTO-FINISH fineness

Nearest frequency peer: fineness (+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.

Long-tail ranks near “filamentous”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

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

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for filamentous
PropertyValue
Headwordfilamentous
LanguageEnglish
Part of speechAdjective
Letters11
Frequency rank#66,663
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “filamentous” in English

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).filamentousfalls in this rarity band:

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

The axis is logarithmic, with each marked tick roughly ten times rarer than the last. Rare peers in the same band: “fineness” (#66,664), “fightback” (#66,661), “finitely” (#66,665). Among 2,507 “F” headwords, “filamentous” is #66,663. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

filamentous is uncommon English at frequency #66,663 among 2,507 “F” headwords, classed as anadjective. Rarity is why readers land here mid-draft. Gloss: "Having the form of threads or filaments; filamented.".

No misspelling variants are generated for filamentous in our index, which points to an orthography that plays by predictable English rules. This entry stands alone in our confusable dataset, since no other headword is close enough in sound or shape to pair with it.

Etymologically, the entry records: From filament + -ous. The correct English form is filamentous, spelled F-I-L-A-M-E-N-T-O-U-S.

Definition

  1. 1
    Having the form of threads or filaments; filamented.

Etymology

From filament + -ous.

This word in other languages

filamenteux(Français)

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 "filamentous"?
"filamentous" is spelled F-I-L-A-M-E-N-T-O-U-S.
What does "filamentous" mean?
As an adjective, "filamentous" means: Having the form of threads or filaments; filamented.
What is the origin of the word "filamentous"?
From filament + -ous. 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 "filamentous", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 11 letters (nearest by frequency rank).

endeavoring#66,638discernable#66,616hollandaise#66,724cunnilingus#66,594

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

Source: FrequencyWords open word-frequency list