In the novel, "California" is described as an island inhabited by a black Amazonian queen, Calafia, and her warriors. It was a place of great wealth and wonder, full of gold and precious stones.
Therefore, the meaning of "California" in English is essentially derived from this fictional island and its fantastical elements.
It's important to note that the word's meaning in English doesn't have a direct translation like a standard dictionary definition. It's more of a cultural and historical reference to the fictional island.