Bridle

part of the tack or harness of a horse, consisting usually of a headstall, bit, and reins.
anything that restrains or curbs:
His common sense is a bridle to his quick temper.
Machinery. a link, flange, or other attachment for limiting the movement of any part of a machine.
Nautical. a rope or chain secured at both ends to an object to be held, lifted, or towed, and itself held or lifted by a rope or chain secured at its center.
a raising up of the head, as in disdain.
to put a bridle on.
to control or hold back; restrain; curb.
to draw up the head and draw in the chin, as in disdain or resentment.
Contemporary Examples

Twitterature Isabel Wilkinson March 31, 2009
The West Bank Through Chinese Eyes Bernard Avishai March 18, 2012
Twitterature Isabel Wilkinson March 31, 2009

Historical Examples

Home-made Toys for Girls and Boys A. Neely Hall
The White Company Arthur Conan Doyle
The Pioneers Katharine Susannah Prichard
Thoroughbreds W. A. Fraser
The Lions of the Lord Harry Leon Wilson
Thoroughbreds W. A. Fraser
The Red Moccasins Morrison Heady

noun
a headgear for a horse, etc, consisting of a series of buckled straps and a metal mouthpiece (bit) by which the animal is controlled through the reins
something that curbs or restrains; check
a Y-shaped cable, rope, or chain, used for holding, towing, etc
(machinery) a device by which the motion of a component is limited, often in the form of a linkage or flange
verb
(transitive) to put a bridle on (a horse, mule, etc)
(intransitive) (of a horse) to respond correctly to the pull of the reins
(transitive) to restrain; curb: he bridled his rage
(intransitive) often foll by at. to show anger, scorn, or indignation
n.
v.