Definition of rein in

The origin of the phrase "rein in" can be traced back to the 16th century, specifically to the world of horse riding. In the Middle Ages, horse-drawn carriages and coaches were common modes of transportation, but horse riding itself was a popular pastime for the noble classes. During horseback riding, the rider used two long leather straps, known as reins, to guide the horse's movement. The reins would be wrapped around the horse's neck and attached to a rein ring on the bit in its mouth. The term "rein in" was originally used in horse-riding to mean "bring the reins together and hold them firmly in each hand to control the horse." In other words, it meant to bring the horse under control and prevent it from galloping off or charging ahead uncontrollably. As the phrase became more widely used, it evolved to apply to other situations in which a person was trying to control or restrict something else, such as a person's behavior or a situation's outcome. Today, the phrase "rein in" is widely used in various contexts, often with the figurative meaning of "restrain" or "stop from excessive behavior." Whether in horse-riding or more general situations, "rein in" helps us to keep things under control, prevent them from running wild, and maintain order and stability.