rein
n. countablen. a long leather strap used to control a horse. You pull on them to tell the animal which way to go or to make it stop.
n. a long, narrow strap attached to a bit and held by the rider or driver, used to control a horse or other animal. Often used metaphorically to describe the power to direct or control a situation.
She pulled on the left rein to turn the horse toward the gate.
The rider kept a firm grip on the rein as the horse began to gallop across the open field.
After the sudden departure of the CEO, the board of directors struggled to decide who should take the reins of the company during the transition period.
As a German surname, borrowed from German Rein, comparable to the first element of several surnames such as Reinhardt, Reinbold, etc., from Proto-Germanic raginą. * As an English surname, variant of Rain. Possibly also a habitational surname related to Rhine.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Commonly used in the plural ('reins') when referring to the set of straps or the concept of control.
free reignfree reinLearners often confuse 'rein' (control strap) with 'reign' (a monarch's rule) in the idiom 'free rein'.
Last updated May 6, 2026