What is Hurdle?

Legal Definition
A hurdle (UK English, limited US English) is a moveable section of light fence. In the United States, terms such as "panel", "pipe panel" or simply "fence section" are used to describe moveable sections of fencing intended for agricultural use and crowd control; "hurdle" refers primarily to fences used as jumping obstacles for steeplechasing with horses or human track and field competition.

Traditional hurdles were made from wattle, but modern designs for fencing are often made of metal. They are used for handling livestock, as decorative fencing, for steeplechasing and in the track and field event of hurdling.
-- Wikipedia
Legal Definition
In English criminal law. A kind of sledge, on which convicted felons were drawn to the place of execution.
-- Black's Law Dictionary
Legal Definition
Eng. law. A species of sledge, used to draw traitors to execution.
-- Bouviers Law Dictionary
Legal Definition
A sledge on which a traitor was dragged to execution. See 4 Bl. Comm. 92.
-- Ballentine's Law Dictionary