To restrict, curtail, curb; to slow down or reduce.

To restrict, curtail, curb.

Loose rein(s), as of a horse. / (figuratively) The absence of constraints; freedom to make decisions.

A piece of cotton or nylon webbing, usually around 25mm wide by about 20 metres (or longer) in length, attached with a swivel to the bridle, lungeing cavesson, or headcollar of a horse to provide control while exercising or training it.

(intransitive) To bring a ridden animal to a halt by pulling on the reins. / (transitive) To fit reins on (a horse) / (transitive) To stop, to cause to come to a halt.

A checkrein.

A rein for drawing the bit upward in the horse's mouth.

A rein used to lead an animal (especially a horse) when there is no rider, or when the rider is young or inexperienced.

The separate rein used to control a bridoon.

A hook on a gig-saddle for holding the checkrein.