嶋:
1. Historically the same as "岛" (island).
2. Land surrounded by water on all sides in rivers, seas, or lakes: islands (嶋屿), half-island (半嶋), sea island (海嶋), island chain (嶋链 - a series of islands arranged in a line).
3. Entering the sea and residing among the islands. — "Records of the Grand Historian: Biography of Tian Dan". The commentary cites Wei Zhao: "A mountain in the sea is called an island." Mountains and islands stand tall. — Cao Cao "Walking out of Summer Gate". The British Isles belong to the region of ice and snow at sea. — Huxley, translated by Yan Fu, "On Evolution".