"Steadicam" is a registered trademark of Tiffen for their camera stabilizers.

In the loosest sense, it refers to a stabilizing mount for a motion-picture camera, which mechanically isolates the movement of the camera from that of the operator, providing a very smooth shot even when the operator is moving quickly over an uneven surface. Many familiar with the general concept use it to refer to the combined assembly of mount and camera.

More from Wikipedia ...