fibreglass
/ˈfaɪbəɡlɑːs/
"fibreglass" is a 10-letter English headword indexed on PlainSpell.
The verdict
“fibreglass” is uncommon English (frequency #51,112 among 18,613 “F” headwords), classed as a noun. The kind of spelling people second-guess.
- #51,112
- frequency rank, English
- 18,613
- “F” headwords
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Silica based glass extruded into fibers that possess a length at least 1000 times greater than their width.
Corpus desk
Index EN-fibreglass · fibreglass · English
fibreglass · rank #51,112 · 0 variants · 0 confusables
- FREQ-RARE #51,112
- LEN-MEGA 10 letters
- VOW-3 3 vowels
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-DENSE 18,613
- PHOTO-FINISH feverishly
Nearest frequency peer: feverishly (-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.
Frequency neighbourhood for “fibreglass”
Lower corpus rank = more everyday usage (inverted bar length for readability)
- fatigues
fatigues
48,895 corpus weight
- feverishly
feverishly
48,891 corpus weight
- fibreglass
fibreglass
48,889 corpus weight
- flaking
flaking
48,887 corpus weight
- flecks
flecks
48,885 corpus weight
- flexor
flexor
48,884 corpus weight
What this shows Bars show where “fibreglass” sits against the nearest ranked English headwords in the FrequencyWords band, not a reprint of letter-browse containment.
| Property | Value |
|---|---|
| Headword | fibreglass |
| Language | English |
| Part of speech | Noun |
| IPA | /ˈfaɪbəɡlɑːs/ |
| Letters | 10 |
| Frequency rank | #51,112 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “fibreglass” sits in English frequency
Rare enough to double-check
fibreglass is uncommon English at frequency #51,112 among 18,613 “F” headwords, classed as anoun, transcribed /ˈfaɪbəɡlɑːs/. Rarity is why readers land here mid-draft. 3 senses are on record.
fibreglass doesn't appear in our generated misspelling index, which points to an orthography that plays by predictable English rules. No confusable counterpart is on file for this word, a sign it's visually distinctive enough not to be mixed up with another word.
Etymologically, the entry records: Compound of fibre + glass. The correct English form is fibreglass, spelled F-I-B-R-E-G-L-A-S-S.
Definition
- 1Silica based glass extruded into fibers that possess a length at least 1000 times greater than their width.
- 2Ellipsis of fibreglass wool.
- 3A composite material made from fine fibres of spun glass held together with resin.
Etymology
Compound of fibre + glass.
Synonyms
This word in other languages
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.
PlainSpell is rendered directly from structured Wiktionary extracts and open word-frequency lists, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 6, 2026. Primary sources: Wiktionary (via kaikki.org) and FrequencyWords.
Frequently Asked Questions
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Similar English words by spelling shape
Same letter count and similar misspelling depth for "fibreglass", not the corpus desk frequency band.
Same letter count
Frequency-ranked English headwords with 10 letters (nearest by frequency rank).
Data Source
Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.