n. A tract of land surrounded by water, whether of the sea, a river, or a lake: in contradistinction to mainland or continent.n. Something resembling an island: as, an island of floating ice.n. A hill rising out of low ground or swampy land, a small clump of woodland in a prairie, or the like.n. A meringue of white of egg and sugar floating in divisions upon soft custard.To cause to become or appear like an island; insulate.To dot as with islands.See Iceland, Iceland dog.n. In anatomy, any circumscribed portion of tissue or aggregation of cells differing in structure from the surrounding parts.Isolated; separate.