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castor1

[kas-ter, kah-ster]
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noun
  1. Also castoreum. a brownish, unctuous substance with a strong, penetrating odor, secreted by certain glands in the groin of the beaver, used in medicine and perfumery.
  2. a hat made of beaver or rabbit fur.
  3. a heavy woolen cloth used mainly for coats.
  4. a beaver.
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Origin of castor1

1350–1400; Middle English < Latin < Greek kástōr beaver

castor2

[kas-ter, kah-ster]
noun
  1. caster(defs 2–5).
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Castor

[kas-ter, kah-ster]
noun Astronomy.
  1. a star of the second magnitude in the constellation Gemini, the more northerly of the two bright stars in this constellation.
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Origin of Castor

named after Castor; see Castor and Pollux
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for castor

Contemporary Examples

Historical Examples

  • For serving, cut into squares, and dust them over with castor sugar.

    The Skilful Cook

    Mary Harrison

  • Dish on a folded napkin, with castor sugar dusted over them.

    The Skilful Cook

    Mary Harrison

  • Mix in gradually the castor sugar and rice, and add the lemon rind.

    The Skilful Cook

    Mary Harrison

  • Beat the white of egg, mix it with the castor sugar, and spread it over the cakes.

    The Skilful Cook

    Mary Harrison

  • To glaze, brush them with a little white of egg, and dust with castor sugar.

    The Skilful Cook

    Mary Harrison


British Dictionary definitions for castor

castor1

noun
  1. the brownish aromatic secretion of the anal glands of a beaver, used in perfumery and medicine
  2. the fur of the beaver
  3. a hat made of beaver or similar fur
  4. a less common name for beaver 1 (def. 1)
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Word Origin

C14: from Latin, from Greek kastōr beaver

castor2

noun
  1. a variant spelling of caster (def. 2), caster (def. 3)
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Castor

noun
  1. the second brightest star, Alpha Geminorum, in the constellation Gemini: a multiple star consisting of six components lying close to the star Pollux. Distance: 52 light years
  2. classical myth See Castor and Pollux
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Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for castor

n.

late 14c., "beaver," from Old French castor (13c.), from Latin castor "beaver," from Greek Kastor, literally "he who excels," name of one of the divine twins (with Pollux), worshipped by women in ancient Greece as a healer and preserver from disease.

His name was given to secretions of the animal (Latin castoreum), used medicinally in ancient times. (Through this association his name replaced the native Latin word for "beaver," which was fiber.) In English, castor is attested in this sense from c.1600. Modern castor oil is first recorded 1746; it is made from seeds of the plant Ricinus communis but supposedly possesses laxative qualities (and taste) similar to those of beaver juice, and thus so named.

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Online Etymology Dictionary, © 2010 Douglas Harper

castor in Science

Castor

[kăstər]
  1. A bright multiple star in the constellation Gemini, with a combined apparent magnitude of 0.08. Scientific name: Alpha Geminorum.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.