The definition of a longe is a long rein for a horse that lets the horse move around the trainer.
A long rein for a horse is an example of a longe.
A long rope fastened to a horse's head and held by the trainer, who causes the horse to move around in a circle.
The use of the longe in training horses.
To put (a horse) through its paces, using a longe.
The training ground for a horse.