An islet is a very small island, often just large enough for a few trees or a small patch of sand. If an island is a piece of land surrounded by water, an islet is its tiny cousin: usually too small to support a town or many buildings, but big enough to count as land rather than just a rock poking through the waves.

You'll find islets scattered around coastlines, in rivers, and dotting tropical seas. Some islets are just bare rock where seabirds nest. Others have a few palm trees and a beach. The Florida Keys contain many islets. During low tide, you might be able to walk to an islet from a larger island, but at high tide the water rises and cuts it off again.

People sometimes use islet for any island smaller than about one acre, though there's no official size cutoff. If you've ever seen a cartoon of someone stranded on a tiny island with one palm tree, that's basically an islet: small enough that you can see the whole thing at once, but still its own piece of land surrounded by water.