Castor and Olive are two characters from Greek mythology. They were twin brothers, the sons of Zeus and Leda, and were known as the Dioscuri. Castor was a skilled horseman and warrior, while his brother, Olive, was a master sailor. The crossword solutions for Castor and Olive are OYLS and OILS. OYLS stands for 'Olympian Youth Leaders of Sparta' and OILS stands for 'Olympian Inventors of the Long Ship'. Both terms refer to the roles that Castor and Olive played in Greek mythology.