castoreum
"castoreum" is a 9-letter English headword indexed on PlainSpell.
The verdict
“castoreum” is uncommon English (outside the top frequency list), classed as a noun. The kind of spelling people second-guess.
- Unranked
- below top-frequency English
- 9
- letters
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - The bitter exudate of the castor sacs of mature beavers, used as a scent mark, and as a tincture in some perfumes.
Corpus desk
Index EN-castoreum · castoreum · English
castoreum · unranked · 0 variants · 0 confusables
- FREQ-UNRANKED Unranked
- LEN-LONG 9 letters
- VOW-4 4 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 | castoreum |
| Language | English |
| Part of speech | Noun |
| Letters | 9 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Long-tail rank of “castoreum” in English
Rare enough to double-check
castoreum is uncommon English outside the top frequency list, classed as anoun. Rarity is why readers land here mid-draft. 2 senses are on record.
castoreum has no tracked misspelling variants, since its letter pattern doesn't lend itself to common typo substitutions. No close-neighbour confusable shows up for this headword in our dataset, which usually means its spelling is distinct enough that readers don't reach for a similar-looking word instead.
Etymologically, the entry records: From Latin castoreum, from Ancient Greek καστόριον (kastórion). The correct English form is castoreum, spelled C-A-S-T-O-R-E-U-M.
Definition
- 1The bitter exudate of the castor sacs of mature beavers, used as a scent mark, and as a tincture in some perfumes.
- 2A hat made from beaver fur.
Recorded use
Wiktionary examplesThese source excerpts show how castoreum appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.
One of the substances tried was castoreum.[…]If I were to judge from my own experience, I would say castoreum has very little therapeutic power, for I have not seen much benefit from its employment in those cases to which this remedy is said to be adapted.
While the role of castoreum as a means of territorial advertisement has been extensively investigated and supported, the possibility of coding for sex information has not yet been excluded.
Etymology
From Latin castoreum, from Ancient Greek καστόριον (kastórion).
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.