noun (1)
cas·​tor | \ ˈka-stər How to pronounce castor (audio) \

Definition of castor

 (Entry 1 of 2)

2 : castoreum
3 : a beaver hat


noun (2)
Cas·​tor | \ ˈka-stər How to pronounce Castor (audio) \

Definition of Castor (Entry 2 of 2)

1 : one of the Dioscuri
2 : the more northern of the two bright stars in Gemini

Examples of castor in a Sentence

Recent Examples on the Web: Noun Among the product' ingredients are pure avocado oil, black castor and rosemary. Alaa Elassar, CNN, 19 June 2021 Facts About one million tons of castor beans are processed every year, worldwide. Cnn Editorial Research, CNN, 27 May 2021 Sacks likes to recommend using something like castor or almond oil to create the same protective barrier on the brow and to help the tint from fading too fast. Audrey Noble, Harper's BAZAAR, 21 Apr. 2021 Coconut, castor, and safflower oils are the stars of this nourishing show, while turmeric and rose clay work to balance and exfoliate even the most sensitive of skin types. Akili King, Vogue, 12 Apr. 2021 Saaem, who holds a Ph.D. in biomedical engineering and worked as the director of advanced research at a biotechnology firm based in Massachusetts, allegedly ordered 100 packets of castor beans online. Mike Brest, Washington Examiner, 17 Mar. 2021 Sahajan’s Lip Karma contains castor, rapeseed and argan oil for some serious moisturization. Kiana Murden, CNN Underscored, 16 Dec. 2020 Formulated with herbal extracts like cedarwood, rosemary, baobab, and castor oils, the Attuning Hair Potion is beloved by many for its nourishing properties and ability to soothe an itchy scalp. Chelsea Hall, Marie Claire, 10 Dec. 2020 The bright spot, maybe the only one, was beaver castor. John Schandelmeier, Anchorage Daily News, 14 Nov. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'castor.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of castor

Noun (1)

14th century, in the meaning defined at sense 1

Noun (2)

15th century, in the meaning defined at sense 1

History and Etymology for castor

Noun (1)

Middle English, from Latin, from Greek kastōr, from Kastōr Castor

Noun (2)

Latin, from Greek Kastōr

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Time Traveler for castor

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The first known use of castor was in the 14th century

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Dictionary Entries Near castor

cast one's lot with



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Last Updated

28 Jun 2021

Cite this Entry

“Castor.” Dictionary, Merriam-Webster, Accessed 30 Jul. 2021.

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