bus
n.— «We hear the low growl of a panther—but it’s the hiss of the brakes of a bus as it comes into shot from screen right. Watching this in the right circumstances, you’ll jump out of your skin…as no doubt audiences in 1943. This technique is known in horror-movie technique as a “bus” in direct reference to this very scene. It’s long since become a cliché, but this is where it first appeared.» —“Cat People (1943)/The Curse of the Cat People” DVDTimes Dec. 12, 2005. (source: Double-Tongued Dictionary)