1) Hedge that bars cattle 
Horse jumping term often used in agility to denote a double-bar spread jump.
An oxer is a type of fence. It is two jumps that you jump as one. The spread (area between the two fences) can very from half a foot to 6 feet, depending how experienced you are!
Parallel bar-type fence with two rails A square oxer has even rails A step or ascending oxer has a lower front rail
A single fence composed of two or three parts to produce a spread, or width, effect. A "square" oxer is equal in height in both the front element of the spread and the back.
Single fence consisting of two elements which make a spread jump