Castor /(?)/
Cas·tor
Castor
n.
Castor
n.
- See Caster, a small wheel.
Castor
n.
- the northernmost of the two bright stars in the constellation Gemini, the other being Pollux. (Astron.)
Castor
n.
- A variety of the mineral called petalite, from Elba. (Min.)