What is a "hack"?

A hack refers to a horse suitable for general riding and leisure activities, such as hacking out in the countryside. Hacks are often well-trained and well-mannered horses, typically used for pleasure riding, showing, and low-level competitions. They are usually calm, obedient, and versatile, and can be ridden by riders of varying skill levels. They may be of any breed or type, and are generally selected for their temperament, conformation, and movement. The term "hack" can also refer to the act of riding a horse out for pleasure or exercise