from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Greek Mythology One of the Dioscuri.
- n. A double star in the constellation Gemini, the brightest star in the group, approximately 46 light-years from Earth.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- proper n. A taxonomic genus within the family Castoridae — the beavers.
- proper n. One of the Dioscuri
- proper n. A double star in the constellation Gemini; alpha (α) Geminorum.
Latin, from Greek Kastōr, twin of Pollux.(American Heritage® Dictionary of the English Language, Fourth Edition)
1398 Old French castor, from Latin castor ("beaver"), from Ancient Greek Κάστωρ (Kastor). (Wiktionary)