Alfred Hitchcock's term for the device or plot element (an item, object, goal, event, or piece of knowledge) that catches the viewer's attention or drives the logic or action of the plot and appears extremely important to the film characters, but often turns out to be insignificant or is to be ignored after it has served its purpose; its derivation is Scottish, meaning a "lion trap" for trapping lions in the lion-less Scottish Highlands (i.e., a trap that means nothing, since it is for an animal where there is no such animal).