castor

See also: Castor

English

Pronunciation

• (Received Pronunciation) IPA^(key): /ˈkɑː.stə/

• Audio (Southern England):

  (file)

• (General American) IPA^(key): /ˈkæs.tɚ/
• Rhymes: -ɑːstə(ɹ), -æstə(ɹ)
• Homophone: caster

Etymology 1

From Middle French castor, from Old French castor (“beaver”), from Latin castor (“beaver”), from Ancient Greek κάστωρ (kástōr), from Doric Greek κάστον (káston, “wood”).

Noun

castor (countable and uncountable, plural castors)

1. A hat made from the fur of the beaver.
   • 1826, [Walter Scott], chapter V, in Woodstock; Or, The Cavalier. […], volume I, Edinburgh: […] [James Ballantyne and Co.] for Archibald Constable and Co.; London: Longman, Rees, Orme, Brown, and Green, →OCLC, page 135:

     I have been always noted for the jaunty manner in which I wear my castor— […]

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.

Synonyms

• (hat): beaver, castoreum (archaic)
• (cloth): beaver

Derived terms

• castorette
• castorin

Related terms

• castoreum

Descendants

• → Egyptian Arabic: كستور (kastūr)

Translations

hat

• Bulgarian: бобро́ва ша́пка f (bobróva šápka)
• Czech: bobrovka (cs) f
• Finnish: majavahattu
• Italian: castoro (it)
• Polish: strój bobrowy (pl) m, kastoreum (pl) n
• Russian: бобро́вая ша́пка f (bobróvaja šápka)

cloth — see beaver

See also

• castor bean
• castor oil
• castor sac

Etymology 2

Named from Greek mythology; see Castor and Pollux. The name pollux was given to another mineral with which it was always found.

Noun

castor (uncountable)

1. (mineralogy) A variety of petalite found in Elba.

Synonyms

• castorite

Etymology 3

Alternative spelling of caster, via cast +‎ -or (the Latinate varient of -er).

Noun

castor (plural castors)

1. (especially UK) Alternative spelling of caster, especially in its senses
   1. A pivoting roller attached to the bottom of furniture to allow it to be moved.
   2. A container with a perforated cap for sprinkling its contents, especially salt, pepper, etc.
      • 1851 November 14, Herman Melville, “The Ramadan”, in Moby-Dick; or, The Whale, 1st American edition, New York, N.Y.: Harper & Brothers; London: Richard Bentley, →OCLC, page 92:

        Mrs. Hussey soon appeared, with a mustard-pot in one hand and a vinegar-cruet in the other, having just broken away from the occupation of attending to the castors, and scolding her little black boy meantime.

Derived terms

• castor sugar
• castored
• castoring

References

“castor”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.

Anagrams

• Castro, Cators, Croats, acrost, actors, co-star, costar, scroat, scrota, tarocs

Asturian

Noun

castor m (plural castores)

1. beaver

Catalan

Etymology

Learned borrowing from Latin castŏrem.

Pronunciation

• IPA^(key): (Northern) [kəsˈtu]
• IPA^(key): (Balearic, Central) [kəsˈto]
• IPA^(key): (Valencia) [kasˈtoɾ]
• IPA^(key): (Northwestern) [kasˈto]

• Audio (Valencia):

  (file)

Noun

castor m (plural castors)

1. beaver

Further reading

• “castor”, in Diccionari de la llengua catalana [Dictionary of the Catalan Language] (in Catalan), second edition, Institute of Catalan Studies [Catalan: Institut d'Estudis Catalans], April 2007

French

castor

Etymology

Inherited from Middle French castor, from Old French castor, borrowed from Latin castor, itself from Ancient Greek κάστωρ (kástōr). Though borrowed into French early on, the word remained a more learned term at first, while bièvre was the popular synonym.

Pronunciation

• IPA^(key): /kas.tɔʁ/

• Audio:

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• Audio (Paris):

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• Audio (France (Vosges)):

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• Audio (France (Lyon)):

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• Audio (France (Somain)):

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• Homophone: castors

Noun

castor m (plural castors)

1. beaver (aquatic mammal)

   Synonym: (archaic) bièvre

2. castor (hat made from beaver fur)
   • 1857, Gustave Flaubert, Madame Bovary […]‎^[1], Paris: Michel Lévy Frères:

     Un amas de guenilles lui recouvrait les épaules, et un vieux castor défoncé, s'arrondissant en cuvette, lui cachait la figure; […] .

     (please add an English translation of this quotation)

Derived terms

• castor commun
• castor d'Eurasie
• castor d'Europe

Further reading

• “castor”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012

Anagrams

• scorât

Galician

Etymology

Derived from Latin castor (“beaver”).

Pronunciation

• IPA^(key): /kasˈtoɾ/

Noun

castor m (plural castores)

1. beaver

   Synonym: befre

Further reading

• “castor”, in Dicionario da Real Academia Galega (in Galician), A Coruña: Royal Galician Academy, 2012–2026

Latin

Etymology

From Ancient Greek κάστωρ (kástōr), from Doric Greek κάστον (káston, “wood”). See also Sanskrit कस्तूरी (kastūrī, “musk”).

Pronunciation

• (Classical Latin) IPA^(key): [ˈkas.tɔr]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈkas.tor]

Noun

castor m (genitive castoris); third declension

1. beaver

Declension

Third-declension noun.

	singular	plural
nominative	castor	castorēs
genitive	castoris	castorum
dative	castorī	castoribus
accusative	castorem	castorēs
ablative	castore	castoribus
vocative	castor	castorēs

Synonyms

• fiber, beber (Late Latin)

Derived terms

• castoreātus
• castoreum
• castorīnātus
• castorīnus

Related terms

• Castor

Descendants

• → Catalan: castor
• → Old French: castor
  • Middle French: castor
    • French: castor
    • → English: castor
• → Friulian: castôr
• → Galician: castor
• → Italian: castoro
• → Portuguese: castor
• → Romanian: castor
• → Spanish: castor

See also

• Castor

References

• “castor”, in Charlton T. Lewis and Charles Short (1879), A Latin Dictionary, Oxford: Clarendon Press
• “castor”, in Charlton T. Lewis (1891), An Elementary Latin Dictionary, New York: Harper & Brothers
• "castor", in Charles du Fresne du Cange, Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
• “castor”, in Gaffiot, Félix (1934), Dictionnaire illustré latin-français, Hachette.
• “castor”, in Harry Thurston Peck, editor (1898), Harper’s Dictionary of Classical Antiquities, New York: Harper & Brothers
• “castor”, in William Smith, editor (1848), A Dictionary of Greek and Roman Biography and Mythology, London: John Murray

Anagrams

• Arctos

Norman

Etymology

Borrowed from French castor, from Latin castor (“beaver”).

Noun

castor m (plural castors)

1. (Jersey) beaver

Portuguese

Etymology

Etymology tree

Ancient Greek κάστωρ (kástōr)

Latin castōremlbor.

Portuguese castor

Learned borrowing from Latin castōrem (“beaver”), from Ancient Greek κάστωρ (kástōr).

Pronunciation

 

• (Brazil) IPA^(key): /kasˈtoʁ/ [kasˈtoh]

• (Brazil) IPA^(key): /kasˈtoʁ/ [kasˈtoh]
  • (São Paulo) IPA^(key): /kasˈtoɾ/
  • (Rio de Janeiro) IPA^(key): /kaʃˈtoʁ/ [kaʃˈtoχ]
  • (Caipira) IPA^(key): /kasˈtoɻ/

 

• (Portugal) IPA^(key): /kɐʃˈtoɾ/

• (Portugal) IPA^(key): /kɐʃˈtoɾ/
  • (Southern Portugal) IPA^(key): /kɐʃˈto.ɾi/

• Audio (Brazil (Caipira)):

  (file)

• Rhymes: -oɾ
• Hyphenation: cas‧tor

Noun

castor m (plural castores)

1. beaver (Castor sp.)
2. fur of a beaver
3. castor (a hat made from the fur of the beaver)

Derived terms

• castor-americano
• castor-de-kellogg
• castor-europeu
• castor-gigante
• castorenho

Further reading

• “castor”, in Dicionário Aulete Digital (in Portuguese), Rio de Janeiro: Lexikon Editora Digital, 2008–2026
• “castor” in Dicionário Aberto based on Novo Diccionário da Língua Portuguesa de Cândido de Figueiredo, 1913
• “castor”, in Michaelis Dicionário Brasileiro da Língua Portuguesa (in Portuguese), São Paulo: Editora Melhoramentos, 2015–2026, →ISBN
• “castor”, in Dicionário Priberam da Língua Portuguesa (in Portuguese), Lisbon: Priberam, 2008–2026

Romanian

Castori

Etymology

Borrowed from French castor and its source, Latin castor, from Ancient Greek κάστωρ (kástōr).

Noun

castor m (plural castori)

1. beaver

   Synonyms: breb (“European beaver”); (less common) biber

Declension

	singular		plural
	indefinite	definite	indefinite	definite
nominative-accusative	castor	castorul	castori	castorii
genitive-dative	castor	castorului	castori	castorilor
vocative	castorule		castorilor

Further reading

• “castor”, in DEX online—Dicționare ale limbii române (Dictionaries of the Romanian language) (in Romanian), 2004–2026

Spanish

Etymology

Derived from Latin castor (“beaver”).

Pronunciation

• IPA^(key): /kasˈtoɾ/ [kasˈt̪oɾ]

• Audio (Colombia):

  (file)

• Rhymes: -oɾ
• Syllabification: cas‧tor

Noun

castor m (plural castores)

1. beaver

Further reading

• “castor”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8.1, Royal Spanish Academy [Spanish: Real Academia Española], 15 December 2025