Island/ˈaɪlənd/ Definition 1 of 4Pro Tip 1/3Size Variance Islands can range from vast landmasses to tiny rocks in the sea, size doesn't define them. Greenland is the world's largest island. Pro Tip 2/3Not Always Tropical Islands exist in all climates, including polar areas, not just warm tropical regions. Iceland is a Nordic island country. Pro Tip 3/3Populated or Not Some islands have large populations, while others are uninhabited. Robinson Crusoe found himself on an uninhabited island.