Which continent is an Island?

If you define an Island as a body of land surrounded by ocean, then technically every landmass is a island, (the Americas, Eurasia plus Africa, Australia and Antarctica, as well as all smaller bodies)

More Scientifically though the terms Continent and Island refer to different sizes of such landmasses. The worlds smallest Continent is Australia, while the worlds largest Island is Greenland. There is no strict means of deciding what landmass is large enough to be a continent.

In simple terms, both the continents of Australia and Antarctica are island continents, being completely surrounded by water.