castor

1 of 2

noun (1)

cas·​tor ˈka-stər 

1

: beaver sense 1a

2

: castoreum

3

: a beaver hat

Castor

2 of 2

noun (2)

Cas·​tor ˈka-stər 

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

There’s also a handful of botanical oils (coconut, peppermint, castor, and babassu seed, to name a few) for additional nutrients. —Kiana Murden, Vogue, 28 Dec. 2024

While the way people are learning about castor is thoroughly modern, the ingredient itself and its use in wellness and beauty trends are decidedly ancient, dating back to early Ayurvedic practices. —Margaux Anbouba, Vogue, 18 Dec. 2024

Additionally, peptides, squalane, castor seed oil, and hemp seed oil are all rich in nutrients and fatty acids that will keep your lips stay moisturized. —Alanna Martine Kilkeary, Glamour, 17 Dec. 2024

It’s made by hand and milled with vibrant pigments in a high-quality, organic castor seed oil which helps soften the lips. —Robin Raven, Forbes, 1 Dec. 2024

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

Phrases Containing castor

• castor bean
• castor oil
• castor-oil plant
• castor sugar

Kids Definition

Castor

noun

Cas·​tor ˈkas-tər 

: 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