Quick answer
Castor is a boy name with Greek roots meaning "to excel, to shine; beaver".
Pronunciation: American English /ˈkæs.təɹ/; British English /ˈkæs.tə/.
Meaning and history
This name comes from the Greek name Κάστωρ (Kastor), possibly related to κέκασμαι ( kekasmai ) meaning "to excel, to shine" (pluperfect κέκαστο ). Alternatively it could be derived from the Greek word κάστωρ (kastor) meaning "beaver", though the legends about Castor do not mention beavers, which were foreign animals to the Greeks. In Greek myth Castor was a son of Zeus and the twin brother of Pollux. The constellation Gemini, which represents the two brothers, contains a star by this name.
Notes and context
Usage: greek mythology | Ancient Greek: Κάστωρ