Castor and Pollux: The "Dioscuri", two heroes of Greek and Roman mythology. Their figures were probably painted or sculptured on the prow of the ship which Luke refers to (Acts 28:11). They were regarded as the tutelary divinities of sailors. They appeared in the heavens as the constellation Gemini.

Noah Webster's New International Dictionary of the English Language

1. (n.) A fixed star of the second magnitude, in the constellation Gemini. Cf. 3d Castor.

2. (n.) Same as Pollucite.