Meaning 1 A structure that rotates on an axle and bears a number of legs. Used in applications where the springing motion involved in legged locomotion is not desired, while simultaneously maintaining the ability to navigate terrain that is impassable to wheeled vehicles.
Meaning 2 A wheel located somewhere on a leg, such as near a joint or on the end of the leg. Used for rolling on surfaces smooth enough to allow wheels to operate. Wheels on the ends of legs are designed to lock up to where they cannot rotate, forming stable feet for the legs when they are engaging in a walking or running gate. Some leg wheels that are on the ends of legs are mounted to the leg via a universal joint, allowing the wheel to turn on its side. Such types of leg wheels generally have geckotech covered toes radiating from or near the wheel hub, so when the wheels are turned on their side they can function as adhesive climbing feet.