castor
/ˈkæs.tɚ/noun
castor is spelled C-A-S-T-O-R: 6 letters and 2 syllables. It appears 1.5 times per million words in written English, the 22,965th most frequent word form (wordfreq, 2021 data). People search “caster vs castor” about 170 times a month (Google, United States). As a noun, castor means “A hat made from the fur of the beaver” (English Wiktionary, September 2026). The plural of castor is castors.
How many letters and syllables are in castor?
| Letters | 6: C-A-S-T-O-R |
|---|---|
| Syllables | 2 (from its American pronunciation) |
| In writing | 1.5 times per million words; the 22,965th most frequent word form |
| Wrong spellings searched | none measured in search |
| Pairs people search | |
| Sounds like | |
| Rhymes with | |
| Same letters |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation and the CMU Pronouncing Dictionary; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media); Bing searches in the United States: the average month from September 2025 to August 2026 (Microsoft Advertising keyword data through DataForSEO, read September 30, 2026); rhymes and same-letter words are computed by PlainSpell from its own word list.
How common is castor?
Castor appears 1.5 times per million words in written English, the 22,965th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce castor?
- UK /ˈkɑːs.tə/
- US /ˈkæs.tɚ/
Castor has 2 syllables (counted from its American pronunciation in the CMU Pronouncing Dictionary).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Vealhurl-castor.wav, Wikimedia Commons (author and licence on each file's page).
Words people confuse with castor
Word pairs people search, with the monthly searches for “a vs b” (G: Google, B: Bing, United States).
Sounds like: caster (Wiktionary's homophone list; some hold only in some accents).
Sources: Google and Bing searches (September 2025 to August 2026, through DataForSEO); English Wiktionary (homophones, alternative spellings).
What rhymes with castor?
9 words on PlainSpell end in the same sounds as castor from its last stressed vowel (/æstəɹ/):
Spelled with the same letters in another order: costar.
Computed by PlainSpell from the pronunciations in the English Wiktionary (dump of September 2, 2026): a rhyme shares every sound from the last stressed vowel to the end; ordered by written frequency (wordfreq 3.1).
Forms of castor
- castors plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does castor mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
A hat made from the fur of the beaver.
- 2
A heavy quality of broadcloth for overcoats.
- 3
Castoreum (bitter exudate of mature beavers).
- 4
Any of various nymphalid butterflies of the genus Ariadne, of Africa and Asia.
- 5
A variety of petalite found in Elba.
- 6
UKA pivoting roller attached to the bottom of furniture to allow it to be moved.
- 7
UKA container with a perforated cap for sprinkling its contents, especially salt, pepper, etc.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Where does castor come from?
From Middle French castor, from Old French castor (“beaver”), from Latin castor (“beaver”), from Ancient Greek κάστωρ (kástōr), from Doric Greek κάστον (káston, “wood”).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).