slapstick

Where it comes from

A slapstick was a theatrical clapper made from two wooden slats joined at one end. When used in a staged blow, the pieces struck one another and produced a conspicuously loud crack, magnifying the sound of the action.

How the meaning developed

The prop belonged to traditions of broad physical comedy, including commedia dell'arte and later pantomime. By the early twentieth century, English was using its name for the whole comic style of exaggerated blows, falls, chases, and physical gags.