The twin brother of Pollux.See Dioscuri
The second brightest star in the constellation Gemini, close to Pollux. It is a multiple star system, the three components visible in a moderate telescope being close binaries.
A reddish-brown oily substance secreted by beavers, used in medicine and perfumes.
- ‘Beavers produce scent from their castor glands that creates a reddish stain on mounds of grass and mud that they build at the water's edge.’
Late Middle English (in the sense beaver): from Old French or Latin, from Greek kastōr.