Thats because his mother gave him the name.
Princess Lila, a goddess, gave birh to Xicor who is half god, half Saiyan. For centuries Princess Lila wanted to create the perfect being. Then, when she heard that Goku, the most powerful being, was training in space, she created an illusional planet. Every illusion on that planet was perfect. To make sure Goku would come to the planet, she made it 10,000 times Earth's normal gravity. He fell for the bait. When he was on the planet, she tried to seduce him, but he resisted to all of her efforts, saying that he was already married to a wonderful wife, Chichi. So, when he was sleeping, Princess Lila entered his dreams. There in his dreams, they made love. After that night, Goku left the planet. Soon she gave birth to Xicor, who was born a Super Saiyan 5. He stopped aging the day he hit 17. Since then, she promissed him he'd get training from his father, GOKU.
=)