ultramafic
"ultramafic" is a 10-letter English headword indexed on PlainSpell.
The verdict
“ultramafic” is uncommon English (frequency #93,275 among 23,789 “U” headwords), classed as an adjective. The kind of spelling people second-guess.
- #93,275
- frequency rank, English
- 23,789
- “U” headwords
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Describing igneous rocks that contain magnesium and iron and only a very small amount of silica, such as are found in the Earth’s mantle.
Corpus desk
Index EN-ultramafic · ultramafic · English
ultramafic · rank #93,275 · 0 variants · 0 confusables
- FREQ-RARE #93,275
- LEN-MEGA 10 letters
- VOW-4 4 vowels
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-DENSE 23,789
- PHOTO-FINISH underlain
Nearest frequency peer: underlain (+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 “ultramafic”
Lower corpus rank = more everyday usage (inverted bar length for readability)
- Turnberry
Turnberry
6,735 corpus weight
- Tyburn
Tyburn
6,732 corpus weight
- ultramafic
ultramafic
6,726 corpus weight
- underlain
underlain
6,724 corpus weight
- unescorted
unescorted
6,722 corpus weight
- unfulfilling
unfulfilling
6,721 corpus weight
What this shows Bars show where “ultramafic” sits against the nearest ranked English headwords in the FrequencyWords band, not a reprint of letter-browse containment.
| Property | Value |
|---|---|
| Headword | ultramafic |
| Language | English |
| Part of speech | Adjective |
| Letters | 10 |
| Frequency rank | #93,275 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “ultramafic” sits in English frequency
Rare enough to double-check
ultramafic is uncommon English at frequency #93,275 among 23,789 “U” headwords, classed as anadjective. Rarity is why readers land here mid-draft. Gloss: "Describing igneous rocks that contain magnesium and iron and only a very small amount of silica, such as are found in the Earth’s mantle.".
We couldn't generate a plausible misspelling set for ultramafic, typically a sign the spelling maps closely to how the word sounds. It is not paired with a close-neighbour confusable in our dataset, which typically means the spelling is too distinctive to be mistaken for another word.
Etymologically, the entry records: From ultra- + mafic. The correct English form is ultramafic, spelled U-L-T-R-A-M-A-F-I-C.
Definition
- 1Describing igneous rocks that contain magnesium and iron and only a very small amount of silica, such as are found in the Earth’s mantle.
Etymology
From ultra- + mafic.
Synonyms
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 "ultramafic", 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.