Leg iron is a term coined for a type of shackle or restraint used to confine a person's ankles together. This type of restraint was commonly used in the past to restrain prisoners or criminals, and hence has become synonymous with imprisonment and confinement. Other similar terms that can be used instead of leg iron include ankle cuff, fetter, shackle, and manacle. These terms have evolved over time and have become more commonly used in modern-day language for restraints of this type. Whatever the term used, the implications remain the same- they are devices used to restrict the movements of an individual, thereby making them less dangerous to those around them.