A wooden frame, consisting of a crossbeam on two uprights, on which are executed by hanging. (Dictionary.com)
A similar structure from which something is suspended. (Dictionary.com)
Execution by hanging: (Dictionary.com)
A wooden structure used, especially in the past, to hang criminals from as a form of execution (=killing as a punishment). (Cambridge Dictionary)
To frighten. (Collins Dictionary)
A frame usually of two upright posts and a transverse beam from which criminals are hanged. (Merriam – Webster)
The London gallows where pirates were hanged.
Gallows Superstitions and the Bodies of the Condemned.
In Defence of the Gallows: Justifications of Capital Punishment in New England Execution Sermons, 1674-1825.