An "appendage" refers to a part that is attached to a larger or more important structure. In biology, this term often describes limbs or other extensions of an organism's body, such as the arms and legs of humans or the wings of birds. Appendages can serve various functions, including movement, grasping, or sensing the environment. In a broader context, appendages can also refer to additional components or attachments in different fields. For example, in engineering, an appendage might be an accessory added to a machine to enhance its capabilities. Overall, appendages play crucial roles in both living organisms and man-made systems.