Canon

From TeeVeePedia, the Internet TV Encyclopedia.

A Canon is a large artillery piece which uses a charge of gunpowder to fire an iron ball at a target. Once used extensively in wars, canons are now typically seen in the arsenals of fanboys and fangirls, who use them against television writers when they try to change the plot of a cult television show too much or in an unpopular way.

The Canon was invented by the same team of Japanese scientists who went on to found the electronics company that bears its name.