castor

1 of 2

noun (1)

cas·​tor ˈka-stər How to pronounce castor (audio)
1
2
3
: a beaver hat

Castor

2 of 2

noun (2)

Cas·​tor ˈka-stər How to pronounce Castor (audio)
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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Noun
Meanwhile, castor seed oil, rambutan extract, and a blend of peptides help to nourish your lashes while coating them with high-impact color. Conçetta Ciarlo, Vogue, 26 Mar. 2025 But there’s also a bit of distracting stunt casting in the form of Kurt Russell as a corrupt mogul named Dob McCoy, who has a special ability to turn locals against each other and ruin their crops, his castor farm an ominous foreshadowing of hell-bent poisonings to come. Ryan Lattanzio, IndieWire, 11 Mar. 2025 Rosemary, castor, argan, and other natural oils have long been praised for their ability to help with hair growth. Alyssa Hui-Anderson, Health, 6 Mar. 2025 This antioxidant-rich option is formulated with coffee, caffeine, castor seed, and argan oil to stimulate hair growth at the follicle. Kiana Murden, Vogue, 21 Jan. 2025 See All Example Sentences for castor

Word History

Etymology

Noun (1)

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

Noun (2)

Latin, from Greek Kastōr

First Known Use

Noun (1)

14th century, in the meaning defined at sense 1

Noun (2)

15th century, in the meaning defined at sense 1

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

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Cite this Entry

“Castor.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/castor. Accessed 18 Apr. 2025.

Kids Definition

Castor

noun
Cas·​tor ˈkas-tər How to pronounce Castor (audio)
: the more northern of the two bright stars in Gemini
Etymology

Noun

from Greek Kastōr (name of one of the twin heroes in mythology) see Word History at gemini

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