corundum
/kəˈɹʌn.dəm/
"corundum" is a 8-letter English headword indexed on PlainSpell.
The verdict
“corundum” is uncommon English (outside the top frequency list), classed as a noun. The kind of spelling people second-guess.
- Unranked
- below top-frequency English
- 8
- letters
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - An extremely hard mineral, a form of aluminum oxide with the chemical formula Al₂O₃, that occurs in the form of the gemstones sapphire and ruby; it is used as an abrasive.
Corpus desk
Index EN-corundum · corundum · English
corundum · unranked · 0 variants · 0 confusables
- FREQ-UNRANKED Unranked
- LEN-LONG 8 letters
- VOW-3 3 vowels
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-THIN "C" 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 | corundum |
| Language | English |
| Part of speech | Noun |
| IPA | /kəˈɹʌn.dəm/ |
| Letters | 8 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Long-tail rank of “corundum” in English
Rare enough to double-check
corundum is uncommon English outside the top frequency list, classed as anoun, transcribed /kəˈɹʌn.dəm/. Rarity is why readers land here mid-draft. Gloss: "An extremely hard mineral, a form of aluminum oxide with the chemical formula Al₂O₃, that occurs in the form of the gemstones sapphire and ruby; it is used as an abrasive.".
We couldn't generate a plausible misspelling set for corundum, which points to an orthography that plays by predictable English rules. Our confusable-pair dataset has no match for it, a sign it's visually distinctive enough not to be mixed up with another word.
Etymologically, the entry records: From Tamil குருந்தம் (kuruntam, “ruby, sapphire”) First attested in the early 18th century. The correct English form is corundum, spelled C-O-R-U-N-D-U-M.
Definition
- 1An extremely hard mineral, a form of aluminum oxide with the chemical formula Al₂O₃, that occurs in the form of the gemstones sapphire and ruby; it is used as an abrasive.
Etymology
From Tamil குருந்தம் (kuruntam, “ruby, sapphire”) First attested in the early 18th century.
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.