An appendage is a part that extends or projects from the main body of something. Your arms and legs are appendages: they're attached to your torso but stick out from it. A bird's wings are appendages. So are a crab's claws, a spider's legs, and an elephant's trunk.

The word comes from biology, where scientists use it to describe any limb or body part that branches off from the central structure. But you'll also hear it used more broadly. A writer might call a short extra section at the end of a book an appendage to the main text. An architect might describe a new addition to a building as an appendage to the original structure.

Sometimes people use the word with a slightly dismissive tone, suggesting something is just tacked on rather than essential. If someone describes themselves as “just an appendage” at a meeting, they mean they feel like an unnecessary addition rather than an important participant. But in biology, appendages are crucial: imagine trying to get through your day without your most useful ones!