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castor

1 American  
[kas-ter, kah-ster] / ˈkæs tər, ˈkɑ stər /

noun

  1. Also 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.


Castor 2 American  
[kas-ter, kah-ster] / ˈkæs tər, ˈkɑ stər /

noun

Astronomy.
  1. a star of the second magnitude in the constellation Gemini, the more northerly of the two bright stars in this constellation.


Castor 1 British  
/ ˈkɑːstə /

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

"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

castor 2 British  
/ ˈkɑːstə /

noun

  1. a variant spelling of caster caster

"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

castor 3 British  
/ ˈkɑːstə /

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

"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

Castor Scientific  
/ kăstər /
  1. A bright multiple star in the constellation Gemini, with a combined apparent magnitude of 0.08. Scientific name: Alpha Geminorum.


Etymology

Origin of castor1

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

Origin of Castor2

Named after Castor; Castor and Pollux

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

“Those, over there, are actually castor bean stalks,” Kleckner said as we zoomed past.

From Los Angeles Times • Nov. 7, 2024

Those oils could replace the reliance of growing dangerous crops, like castor.

From Science Daily • Apr. 30, 2024

Other formulas are based on plant oils, including castor bean, cedarwood, clove and peppermint.

From Seattle Times • May 20, 2023

This is, in some sense, castor oil to swallow.

From Washington Post • Feb. 28, 2023

“A fermented mixture of corn, castor oil, eucalyptus extract, menthol, iron, potassium, and calcium,” Hattie Mae answered.

From "Moon Over Manifest" by Clare Vanderpool