castoreum
"castoreum" is a 9-letter English headword indexed on PlainSpell.
The verdict
“castoreum” is outside the top-ranked English vocabulary, used as a noun - the kind of word writers most often double-check.
- Unranked
- below top-frequency English
- 9
- letters
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - The bitter exudate of the castor sacs of mature beavers, used as a scent mark, and as a tincture in some perfumes.
| Property | Value |
|---|---|
| Headword | castoreum |
| Language | English |
| Part of speech | Noun |
| Letters | 9 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “castoreum” sits in English frequency
Spelling & Dictionary Insight
The English entry for castoreum is 9 letters long, classified as a noun. It sits outside the most-frequent rank tiers, which is often why uncommon words generate more spelling variants per reader. Wiktionary records 2 distinct senses for this headword, so context determines which meaning a reader should apply.
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.
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.
Frequently Asked Questions
How do you spell "castoreum"?
What does "castoreum" mean?
What is the origin of the word "castoreum"?
Is PlainSpell free to use?
Using “castoreum”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is C-A-S-T-O-R-E-U-M - every other letter order is a misspelling in standard orthography.
- Browse more English words and confusable pairs in the same reference. English words
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.