What is "scold's bridle"

n. An iron framework that encloses the head, once used as a form of public humiliation for a woman

A scold's bridle, sometimes called a brank's bridle or simply branks, was an instrument of punishment used primarily on women, as a form of torture and public humiliation. The device was an iron muzzle in an iron framework that enclosed the head. A bridle-bit (or curb-plate), about 2 inches long and 1 inch broad, projected into the mouth and pressed down on top of the tongue.

The curb-plate was frequently studded with spikes, so that if the offender moved her tongue, it inflicted pain and made speaking impossible. Wives who were seen as witches, shrews and scolds, were forced to wear the branks, locked onto their head.