rarefaction
"rarefaction" is a 11-letter English headword indexed on PlainSpell.
The verdict
“rarefaction” is uncommon English (outside the top frequency list), classed as a noun. The kind of spelling people second-guess.
- Unranked
- below top-frequency English
- 11
- letters
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - A reduction in the density of a material, especially that of a fluid.
Corpus desk
Index EN-rarefaction · rarefaction · English
rarefaction · unranked · 0 variants · 0 confusables
- FREQ-UNRANKED Unranked
- LEN-MEGA 11 letters
- VOW-5 5 vowels
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-THIN "R" thin
- PHOTO-UNK Peer pending
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.
| Property | Value |
|---|---|
| Headword | rarefaction |
| Language | English |
| Part of speech | Noun |
| Letters | 11 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Long-tail rank of “rarefaction” in English
Rare enough to double-check
rarefaction is uncommon English outside the top frequency list, classed as anoun. Rarity is why readers land here mid-draft. Gloss: "A reduction in the density of a material, especially that of a fluid.".
Zero misspellings are on record for rarefaction in our index, and the word's spelling is regular enough that our generator found nothing worth flagging. 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 Middle French raréfaction. By surface analysis, rarefy + -faction. The correct English form is rarefaction, spelled R-A-R-E-F-A-C-T-I-O-N.
Definition
- 1A reduction in the density of a material, especially that of a fluid.
Recorded use
Wiktionary exampleThese source excerpts show how rarefaction appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.
[T]his ſeal'd vial, being broken under water, ſuck'd in a conſiderable quantity of it, whether, becauſe of ſome little rarefaction of the Air included in the ſealing, or becauſe of the infrigidation of that Air by the ſnow, or for both theſe Reaſons, or any other, I ſhall not Now diſpute.
Etymology
From Middle French raréfaction. By surface analysis, rarefy + -faction.
Antonyms
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). See the methodology for how each field is sourced and updated.