Plain English Meaning
A simple unpowered aircraft made of a fabric wing on a frame. The pilot hangs underneath in a harness and steers by shifting their body weight from side to side or forward and back.
Full Definition
A non-powered, foot-launched ultralight aircraft consisting of a fabric wing stretched over a rigid frame, from which the pilot is suspended in a harness and controls flight by shifting body weight to change the aircraft's center of gravity relative to the wing.
Context Anchor
Seen in discussions of aircraft axes, stability, and control, where the same basic pitch, roll, and ideas apply even to very simple aircraft.