7. [In this sense prob. For older spaddle, a dim. Of spade] See Paddle staff (b), below. Paddle beam, one of two large timbers supporting the spring beam and paddle box of a steam vessel. Paddle board. See Paddle. Paddle box, the structure inclosing the upper part of the paddle wheel of a steam vessel. Paddle shaft, the revolving shaft which carries the paddle wheel of a steam vessel. Paddle staff. A staff tipped with a broad blade, used by mole catchers. A long-handled spade used to clean a plowshare; called also plow staff. Paddle steamer, a steam vessel propelled by paddle wheels, in distinction from a screw propeller. Paddle wheel, the propelling wheel of a steam vessel, having paddles (or floats) on its circumference, and revolving in a vertical plane parallel to the vessel's length.