No, it wasn’t ominously named, it was just meant to be used in cemeteries. It’s what is known as a set gun, which is basically a gun meant to be used as a booby trap, triggered by a trip wire of some kind attached to the firing mechanism. People began using them in the 15th century to defend camps against bears, wolves, and other intruders.
In the 1700s, these devices were repurposed to deal with the big problem of grave robbing. At that time, surgeons and medical students could only legally dissect executed criminals or those who had donated their bodies to science (of which, there weren’t many). So, a black market for bodies sprang up, with thieves liberating fresh bodies from their graves and selling them to people in white coats. Cue the lightning and ominous Universal Studios music.
As a response, a cemetery keeper would load a set gun and arm it at a new grave overnight until he returned in the morning. The devices were intended to be disarmed during the day, and mourners and visitors were supposedly aware of their presence. Grave robbers would sometimes send scouts dressed as mourners to see if a new grave was rigged with a cemetery gun, so keepers began setting them up as late as possible, even after dark.
One of the most popular designs of cemetery gun called for a large-bore, bell-mouthed, flint-locked smoothbore barrel affixed to a block of wood. On the bottom of the block were one or more iron spikes, used to drive the weapon into the ground. Up to three wires could be attached to the trigger and set up to defend an area.
It was up to the cemetery keeper to load the smoothbores with rock salt, bird shot, or heavy shot.
And they weren’t free, or even cheap. Patrons would rent them by the week for their loved one’s grave, so usually cadavers from the poor classes of society were consequently stolen in the night.
Cemetery guns were outlawed in Britain in 1827, because of their indiscriminate nature. Turns out, a lot of innocent people were maimed or killed by cemetery guns.
There is even a cemetery gun dated to 1710, on display at the Museum of Mourning Art at the Arlington National Cemetery in Drexel Hill, Pennsylvania. It was mounted on a mechanism that allowed it to spin freely and was meant to mounted at the foot of a grave with the tripwires strung in an arc around its position.