an area of land surrounded by water and smaller than a continent

This island is made mainly of coal and surrounded by fish. Only an organizing genius could produce a shortage of coal and fish at the same time — Aneurin Bevan

something that is isolated or surrounded, like an island is by water

No man is an island, entire of itself; every man is a piece of the continent, a part of the main — John Donne

= traffic island

an isolated superstructure on the deck of a ship, esp an aircraft carrier

in anatomy, a body part or group of cells that is structurally different from its surroundings