ninth island
 n.— «“It’s poi,” he laughed. This was one of the reasons Bob came to the California Hotel, aka Hawaii’s ninth island. “Try some? The saimin noodles are also good.”» —“Hawaiians flock to California Hotel for island comforts in the desert” by Irene Lechowitzky San Diego Union-Tribune (California) Oct. 12, 2003. (source: Double-Tongued Dictionary)