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castor
castornounAlso a brownish, unctuous substance with a strong, penetrating odor, secreted by certain glands in the groin of the beaver, used in medicine and perfumery.
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Castor
Castornouna star of the second magnitude in the constellation Gemini, the more northerly of the two bright stars in this constellation.
castor
1 Americannoun
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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.
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a hat made of beaver or rabbit fur.
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a heavy woolen cloth used mainly for coats.
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a beaver.
noun
noun
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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
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classical myth See Castor and Pollux
noun
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the brownish aromatic secretion of the anal glands of a beaver, used in perfumery and medicine
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the fur of the beaver
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a hat made of beaver or similar fur
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a less common name for beaver 1
noun
Other Word Forms
Noun Inflected Forms
Etymology
Origin of castor1
1350–1400; Middle English < Latin < Greek kástōr beaver
Origin of Castor2
Named after Castor; see 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.
See Examples For:
The invasive species they brought — like black mustard, tree tobacco and castor bean — slowly crept into the ecosystem.
From Los Angeles Times ● Dec. 14, 2024
The modified Arabidopsis overcame metabolic bottlenecks and produced significant amounts of an oil similar to castor oil that it doesn't naturally produce.
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
Back then, beaver fur hats were worn everywhere and beaver castor — the wax from beaver glands — was in high demand.
From Washington Post ● Dec. 13, 2022
Without a word, a somber woman slid the glass aside and handed each of us a large cup of castor oil.
From "Tasting the Sky" by Ibtisam Barakat
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Castor cited what she described as reckless attacks on other renewable-energy projects—such as wind power—and the independence of the NRC.
From The Wall Street Journal ● Jan. 8, 2026
The highest ever Powerball jackpots were both won in California — in Nov. 2022 when Edwin Castor of Altadena purchased a ticket worth $2.04 billion and in Oct.
From Los Angeles Times ● Aug. 25, 2025
In a dire message that echoed throughout the state, Tampa Mayor Jane Castor said Milton would be “literally catastrophic” to the coastal city.
From BBC ● Oct. 10, 2024
"I’ve said many times that if you want to pick a fight with Mother Nature, she’s winning 100 percent of the time," Tampa Mayor Jane Castor said in a press conference Tuesday.
From Salon ● Oct. 9, 2024
“There’s no aerial footage. Boggs must have been right about their hovercraft capacity,” says Castor.
From "Mockingjay" by Suzanne Collins
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As for the metallic pepperpot-shaped aliens, created by designer Raymond Cusick, Ms Webb remembers rehearsals with actors "trolleying" around on castors in just the bottom halves of the characters that would become The Doctor's nemesis.
From BBC ● Dec. 21, 2023
Honours ended up even, though the smooth-striding Everett glided round as if on castors, while the solidly carved sprint specialist noticeably sagged in his final strides.
From The Guardian ● May 29, 2020
It's odd at first; Stewart seems dazed by the noisiness of the production, to be moving as if on castors.
From Los Angeles Times ● Nov. 4, 2016
The sculptural giltwood pedestal includes leopard masks above three paw feet that conceal recessed brass castors.
From Architectural Digest ● Jan. 14, 2015
Most trappers prefer to keep the castors for scent, as it is attractive to many animals.
From Science of Trapping Describes the Fur Bearing Animals, Their Nature, Habits And Distribution, With Practical Methods For Their Capture by Kreps, Elmer Harry
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.