castor

[ kas-ter, kah-ster ]

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.

  1. a heavy woolen cloth used mainly for coats.

  2. a beaver.

Origin of castor

1
1350–1400; Middle English <Latin <Greek kástōr beaver

Words Nearby castor

Other definitions for Castor (2 of 2)

Castor
[ kas-ter, kah-ster ]

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

Origin of Castor

2
Named after Castor;see Castor and Pollux

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use castor in a sentence

British Dictionary definitions for castor (1 of 3)

castor1

/ (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

  1. a hat made of beaver or similar fur

  2. a less common name for beaver 1 (def. 1)

Origin of castor

1
C14: from Latin, from Greek kastōr beaver

British Dictionary definitions for castor (2 of 3)

castor2

/ (ˈkɑːstə) /


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

British Dictionary definitions for Castor (3 of 3)

Castor

/ (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

Scientific definitions for Castor

Castor

[ kăstər ]


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

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.