A more thorough explanation:

Definition: A double gibbet is a type of gallows used for executing criminals or suspending their bodies after death as a warning to others. It consists of a post with two arms extending from the top, resembling a capital "T".

One example of a double gibbet can be found in the Tower of London, where it was used to hang two Scottish lords, the Earl of Bothwell and the Earl of Huntly, in 1594. Their bodies were left hanging for several years as a warning to other potential rebels.

Another example is the double gibbet used in the execution of the notorious highwayman, Dick Turpin, in 1739. His body was left hanging on the gibbet for over a year as a deterrent to other criminals.

These examples illustrate how the double gibbet was used as a form of punishment and public display of justice in the past. The sight of the bodies left hanging on the gibbet was meant to deter others from committing similar crimes.