A land mass, especially one smaller than a continent, entirely surrounded by water. Something resembling an island, especially in being isolated or surrounded, as: An unattached kitchen counter providing easy access from all sides. A raised curbed area, often used to delineate rows of parking spaces or lanes of traffic. The superstructure of a ship, especially an aircraft carrier. Anatomy A cluster of cells differing in structure or function from the cells constituting the surrounding tissue. To make into or as if into an island; insulate: a secluded mansion, islanded by shrubbery and fences.